;-------------------------------------------------------------------------------------------- .program POSITIVE_CAPTURE pull out x 32 ;read capture length .wrap_target in pins 32 ;read sample jmp pin POST_CAPTURE ;exit wrap if pin is set .wrap POST_CAPTURE: in pins 32 ;read sample jmp x-- POST_CAPTURE ;loop if more samples needed irq 0 ;notify to the main program that we have finished capturing LOCK: jmp LOCK ;block the program ;-------------------------------------------------------------------------------------------- .program NEGATIVE_CAPTURE .wrap_target pull out x 32 ;read capture length PRE_CAPTURE: in pins 32 ;read sample jmp pin PRE_CAPTURE ;loop if pin is set POST_CAPTURE: in pins 32 ;read sample jmp x-- POST_CAPTURE ;loop if more samples needed irq 0 ;notify to the main program that we have finished capturing LOCK: jmp LOCK ;block the program .wrap ;-------------------------------------------------------------------------------------------- .program COMPLEX_CAPTURE pull out x 32 ;read capture length wait irq 7 ;wait for trigger program to be ready .wrap_target in pins 29 ;read sample jmp pin POST_CAPTURE ;exit wrap if pin is set .wrap POST_CAPTURE: in pins 29 ;read sample jmp x-- POST_CAPTURE ;loop if more samples needed irq 0 ;notify to the main program that we have finished capturing LOCK: jmp LOCK ;block the program ;-------------------------------------------------------------------------------------------- .program FAST_CAPTURE pull out x 32 ;read capture length .wrap_target in pins 29 ;read sample jmp pin POST_CAPTURE ;exit wrap if pin is set .wrap POST_CAPTURE: in pins 29 ;read sample jmp x-- POST_CAPTURE ;loop if more samples needed irq 0 ;notify to the main program that we have finished capturing LOCK: jmp LOCK ;block the program ;-------------------------------------------------------------------------------------------- ;--------Kept only for reference, the program is stored in volatile memory as it must-------- ;---------be modified for concrete trigger parameters.--------------------------------------- ;-------------------------------------------------------------------------------------------- ;.program COMPLEX_TRIGGER ; pull ; out x 32 ;read trigger value ; set pins 0 ;set trigger pin to low ; irq 7 ;Release capture program ;TRIGGER_LOOP: ; mov osr, pins ;read pin status to output shift register ; out y, 4 ;output 4 bits to Y (writes 32 bits) ; jmp x!=y TRIGGER_LOOP ;loop if trigger not met ; set pins 1 ;set trigger pin to high (trigger met) ;LOCK: ; jmp LOCK ;block program % c-sdk { #include "../LogicAnalyzer_Build_Settings.h" #include "hardware/gpio.h" #include "hardware/dma.h" #include "hardware/irq.h" #include "string.h" #include "hardware/sync.h" typedef enum { MODE_8_CHANNEL, MODE_16_CHANNEL, MODE_24_CHANNEL } CHANNEL_MODE; //Static variables for the PIO programs static PIO capturePIO; static PIO triggerPIO; static uint sm_Capture; static uint captureOffset; static uint sm_Trigger; static uint triggerOffset; //Static variables for DMA channels static uint32_t dmaPingPong0; static uint32_t dmaPingPong1; static uint32_t dmaPingPong2; static uint32_t dmaPingPong3; //Static information of the last capture static uint8_t lastCapturePins[24]; //List of captured pins static uint8_t lastCapturePinCount; //Count of captured pins static uint32_t lastTriggerCapture; //Moment where the trigger happened inside the circular pre buffer static uint32_t lastPreSize; //Pre-trigger buffer size static uint32_t lastPostSize; //Post-trigger buffer size static bool lastTriggerInverted; //Inverted? static uint8_t lastTriggerPin; static uint32_t lastStartPosition; static bool lastCaptureComplexFast; static uint8_t lastCaptureType; static uint8_t lastTriggerPinBase; static uint32_t lastTriggerPinCount; static uint32_t lastTail; static CHANNEL_MODE lastCaptureMode = MODE_8_CHANNEL; //Static information of the current capture static bool captureFinished; static bool captureProcessed; //Pin mapping, used to map the channels to the PIO program //Could be stored into flash memory but it causes problems //Channel25 (array pos 24) is only used for the external trigger and the simple capture program //Any other usage will cause an error const uint8_t pinMap[] = {2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,26,27,28,1}; //Main capture buffer, aligned at a 32k boundary, to use the maxixmum ring size supported by DMA channels static uint8_t captureBuffer[128 * 1024] __attribute__((aligned(32768))); //----------------------------------------------------------------------------- //--------------Complex trigger PIO program------------------------------------ //----------------------------------------------------------------------------- #define COMPLEX_TRIGGER_wrap_target 0 #define COMPLEX_TRIGGER_wrap 8 #define CAPTURE_TYPE_SIMPLE 0 #define CAPTURE_TYPE_COMPLEX 1 #define CAPTURE_TYPE_FAST 2 uint16_t COMPLEX_TRIGGER_program_instructions[] = { // .wrap_target 0x80a0, // 0: pull block 0x6020, // 1: out x, 32 0xe000, // 2: set pins, 0 0xc007, // 3: irq nowait 7 0xa0e0, // 4: mov osr, pins 0x6044, // 5: out y, 4 0x00a4, // 6: jmp x != y, 4 0xe001, // 7: set pins, 1 0x0008, // 8: jmp 8 // .wrap }; struct pio_program COMPLEX_TRIGGER_program = { .instructions = COMPLEX_TRIGGER_program_instructions, .length = 9, .origin = -1, }; static inline pio_sm_config COMPLEX_TRIGGER_program_get_default_config(uint offset) { pio_sm_config c = pio_get_default_sm_config(); sm_config_set_wrap(&c, offset + COMPLEX_TRIGGER_wrap_target, offset + COMPLEX_TRIGGER_wrap); return c; } //----------------------------------------------------------------------------- //--------------Complex trigger PIO program END-------------------------------- //----------------------------------------------------------------------------- //----------------------------------------------------------------------------- //--------------Fast trigger PIO program--------------------------------------- //----------------------------------------------------------------------------- #define FAST_TRIGGER_wrap_target 0 #define FAST_TRIGGER_wrap 31 uint16_t FAST_TRIGGER_program_instructions[32]; struct pio_program FAST_TRIGGER_program = { .instructions = FAST_TRIGGER_program_instructions, .length = 32, .origin = 0, }; static inline pio_sm_config FAST_TRIGGER_program_get_default_config(uint offset) { pio_sm_config c = pio_get_default_sm_config(); sm_config_set_wrap(&c, offset + FAST_TRIGGER_wrap_target, offset + FAST_TRIGGER_wrap); sm_config_set_sideset(&c, 1, false, false); return c; } //Creates the fast trigger PIO program uint8_t create_fast_trigger_program(uint8_t pattern, uint8_t length) { //This creates a 32 instruction jump table. Each instruction is a MOV PC, PINS except for the addresses that //match the specified pattern. uint8_t i; uint8_t mask = (1 << length) - 1; //Mask for testing address vs pattern uint8_t first = 255; for(i = 0; i < 32; i++) { if((i & mask) == pattern) FAST_TRIGGER_program_instructions[i] = 0x1000 | i; //JMP i SIDE 1 else { FAST_TRIGGER_program_instructions[i] = 0xA0A0; //MOV PC, PINS SIDE 0 first = i; } } return first; } //----------------------------------------------------------------------------- //--------------Fast trigger PIO program END----------------------------------- //----------------------------------------------------------------------------- //Find the last captured sample index uint32_t find_capture_tail() { int transferCount; switch(lastCaptureMode) { case MODE_8_CHANNEL: transferCount = 32768; break; case MODE_16_CHANNEL: transferCount = 16384; break; case MODE_24_CHANNEL: transferCount = 8192; break; } //Add a delay in case the transfer is still in progress (just a safety measure, should not happen) //This is a massive delay in comparison to the needs of the DMA channel, but hey, 5ms is not going to be noticed anywhere :D busy_wait_ms(5); uint32_t busy_channel = 0xFFFFFFFF; uint32_t busy_offset = 0xFFFFFFFF; //First we need to determine which DMA channel is busy (in the middle of a transfer) if(dma_channel_is_busy(dmaPingPong0)) { busy_channel = dmaPingPong0; busy_offset = 0; } if(dma_channel_is_busy(dmaPingPong1)) { busy_channel = dmaPingPong1; busy_offset = transferCount; } if(dma_channel_is_busy(dmaPingPong2)) { busy_channel = dmaPingPong2; busy_offset = transferCount * 2; } if(dma_channel_is_busy(dmaPingPong3)) { busy_channel = dmaPingPong3; busy_offset = transferCount * 3; } //No channel busy?? WTF??? if(busy_channel == 0xFFFFFFFF) return 0xFFFFFFFF; //Ok, now we need to know at which transfer the DMA is. The value equals to MAX_TRANSFERS - TRANSFERS_LEFT. int32_t transfer = transferCount - dma_channel_hw_addr(busy_channel)->transfer_count; //Now compute the last capture position transfer = (transfer + busy_offset) - 1; //Wrap around? if(transfer < 0) transfer = (transferCount * 4) - 1; //Our capture absolute last position return (uint32_t)transfer; } //Disable the trigger GPIOs to avoid triggering again a chained device void disable_gpios() { gpio_deinit(0); gpio_deinit(1); for(uint8_t i = 0; i < lastCapturePinCount; i++) gpio_deinit(lastCapturePins[i]); } //Triggered when a fast capture ends void fast_capture_completed() { //Disable the GPIO's disable_gpios(); //Mark the capture as finished captureFinished = true; lastTail = find_capture_tail(); //Abort DMA channels dma_channel_abort(dmaPingPong0); dma_channel_abort(dmaPingPong1); dma_channel_abort(dmaPingPong2); dma_channel_abort(dmaPingPong3); //Clear PIO interrupt 0 and unhook handler pio_interrupt_clear(capturePIO, 0); irq_set_enabled(pio_get_dreq(capturePIO, sm_Capture, false), false); //Disable all DMA channels dma_channel_unclaim(dmaPingPong0); dma_channel_unclaim(dmaPingPong1); dma_channel_unclaim(dmaPingPong2); dma_channel_unclaim(dmaPingPong3); //Stop PIO capture program and clear pio_sm_set_enabled(capturePIO, sm_Capture, false); pio_sm_unclaim(capturePIO, sm_Capture); pio_remove_program(capturePIO, &FAST_CAPTURE_program, captureOffset); //Stop PIO trigger program and clear pio_sm_set_enabled(triggerPIO, sm_Trigger, false); pio_sm_set_pins(triggerPIO, sm_Trigger, 0); pio_sm_unclaim(triggerPIO, sm_Trigger); pio_remove_program(triggerPIO, &FAST_TRIGGER_program, triggerOffset); } //Check if the capture has finished, this is done because the W messes the PIO interrupts void check_fast_interrupt() { if(lastCaptureType == CAPTURE_TYPE_FAST && capturePIO->irq & 1) fast_capture_completed(); } //Triggered when a complex capture ends void complex_capture_completed() { //Disable the GPIO's disable_gpios(); //Mark the capture as finished captureFinished = true; lastTail = find_capture_tail(); //Abort DMA channels dma_channel_abort(dmaPingPong0); dma_channel_abort(dmaPingPong1); dma_channel_abort(dmaPingPong2); dma_channel_abort(dmaPingPong3); //Clear PIO interrupt 0 and unhook handler pio_interrupt_clear(capturePIO, 0); irq_set_enabled(PIO0_IRQ_0, false); irq_set_enabled(pio_get_dreq(capturePIO, sm_Capture, false), false); irq_remove_handler(PIO0_IRQ_0, complex_capture_completed); //Disable all DMA channels dma_channel_unclaim(dmaPingPong0); dma_channel_unclaim(dmaPingPong1); dma_channel_unclaim(dmaPingPong2); dma_channel_unclaim(dmaPingPong3); //Stop PIO capture program and clear pio_sm_set_enabled(capturePIO, sm_Capture, false); pio_sm_unclaim(capturePIO, sm_Capture); pio_remove_program(capturePIO, &COMPLEX_CAPTURE_program, captureOffset); //Stop PIO trigger program and clear pio_sm_set_enabled(capturePIO, sm_Trigger, false); pio_sm_set_pins(capturePIO, sm_Trigger, 0); pio_sm_unclaim(capturePIO, sm_Trigger); pio_remove_program(capturePIO, &COMPLEX_TRIGGER_program, triggerOffset); } //Triggered when a simple capture ends void simple_capture_completed() { //Disable the GPIO's disable_gpios(); //Mark the capture as finished captureFinished = true; lastTail = find_capture_tail(); //Abort DMA channels dma_channel_abort(dmaPingPong0); dma_channel_abort(dmaPingPong1); dma_channel_abort(dmaPingPong2); dma_channel_abort(dmaPingPong3); //Clear PIO interrupt 0 and unhook handler pio_interrupt_clear(capturePIO, 0); irq_set_enabled(PIO0_IRQ_0, false); irq_set_enabled(pio_get_dreq(capturePIO, sm_Capture, false), false); irq_remove_handler(PIO0_IRQ_0, simple_capture_completed); dma_channel_unclaim(dmaPingPong0); dma_channel_unclaim(dmaPingPong1); dma_channel_unclaim(dmaPingPong2); dma_channel_unclaim(dmaPingPong3); //Stop PIO program and clear pio_sm_set_enabled(capturePIO, sm_Capture, false); pio_sm_unclaim(capturePIO, sm_Capture); if(lastTriggerInverted) pio_remove_program(capturePIO, &POSITIVE_CAPTURE_program, captureOffset); else pio_remove_program(capturePIO, &NEGATIVE_CAPTURE_program, captureOffset); } //Configure the four DMA channels void configureCaptureDMAs(CHANNEL_MODE channelMode) { enum dma_channel_transfer_size transferSize; uint32_t transferCount; switch(channelMode) { case MODE_8_CHANNEL: transferSize = DMA_SIZE_8; transferCount = 32768; break; case MODE_16_CHANNEL: transferSize = DMA_SIZE_16; transferCount = 16384; break; case MODE_24_CHANNEL: transferSize = DMA_SIZE_32; transferCount = 8192; break; } //Claim four DMA channels, each channel writes to 32Kb of the buffer (8192 samples) as that's the maximum ring size supported dmaPingPong0 = dma_claim_unused_channel(true); dmaPingPong1 = dma_claim_unused_channel(true); dmaPingPong2 = dma_claim_unused_channel(true); dmaPingPong3 = dma_claim_unused_channel(true); //Configure first capture DMA dma_channel_config dmaPingPong0Config = dma_channel_get_default_config(dmaPingPong0); channel_config_set_read_increment(&dmaPingPong0Config, false); //Do not increment read address channel_config_set_write_increment(&dmaPingPong0Config, true); //Increment write address channel_config_set_transfer_data_size(&dmaPingPong0Config, transferSize); //Transfer 32 bits each time channel_config_set_chain_to(&dmaPingPong0Config, dmaPingPong1); //Chain to the second dma channel channel_config_set_dreq(&dmaPingPong0Config, pio_get_dreq(capturePIO, sm_Capture, false)); //Set DREQ as RX FIFO channel_config_set_ring(&dmaPingPong0Config, true, 15); //Ring at 32768 bytes //Configure second capture DMA dma_channel_config dmaPingPong1Config = dma_channel_get_default_config(dmaPingPong1); channel_config_set_read_increment(&dmaPingPong1Config, false); //Do not increment read address channel_config_set_write_increment(&dmaPingPong1Config, true); //Increment write address channel_config_set_transfer_data_size(&dmaPingPong1Config, transferSize); //Transfer 32 bits each time channel_config_set_chain_to(&dmaPingPong1Config, dmaPingPong2); //Chain to the third dma channel channel_config_set_dreq(&dmaPingPong1Config, pio_get_dreq(capturePIO, sm_Capture, false)); //Set DREQ as RX FIFO channel_config_set_ring(&dmaPingPong1Config, true, 15); //Ring at 32768 bytes //Configure third capture DMA dma_channel_config dmaPingPong2Config = dma_channel_get_default_config(dmaPingPong2); channel_config_set_read_increment(&dmaPingPong2Config, false); //Do not increment read address channel_config_set_write_increment(&dmaPingPong2Config, true); //Increment write address channel_config_set_transfer_data_size(&dmaPingPong2Config, transferSize); //Transfer 32 bits each time channel_config_set_chain_to(&dmaPingPong2Config, dmaPingPong3); //Chain to the fourth dma channel channel_config_set_dreq(&dmaPingPong2Config, pio_get_dreq(capturePIO, sm_Capture, false)); //Set DREQ as RX FIFO channel_config_set_ring(&dmaPingPong2Config, true, 15); //Ring at 32768 bytes //Configure fourth capture DMA dma_channel_config dmaPingPong3Config = dma_channel_get_default_config(dmaPingPong3); channel_config_set_read_increment(&dmaPingPong3Config, false); //Do not increment read address channel_config_set_write_increment(&dmaPingPong3Config, true); //Increment write address channel_config_set_transfer_data_size(&dmaPingPong3Config, transferSize); //Transfer 32 bits each time channel_config_set_chain_to(&dmaPingPong3Config, dmaPingPong0); //Chain to the first dma channel channel_config_set_dreq(&dmaPingPong3Config, pio_get_dreq(capturePIO, sm_Capture, false)); //Set DREQ as RX FIFO channel_config_set_ring(&dmaPingPong3Config, true, 15); //Ring at 32768 bytes //Configure the DMA channels dma_channel_configure(dmaPingPong3, &dmaPingPong3Config, &captureBuffer[32768 * 3], &capturePIO->rxf[sm_Capture], transferCount, false); //Configure the channel dma_channel_configure(dmaPingPong2, &dmaPingPong2Config, &captureBuffer[32768 * 2], &capturePIO->rxf[sm_Capture], transferCount, false); //Configure the channel dma_channel_configure(dmaPingPong1, &dmaPingPong1Config, &captureBuffer[32768], &capturePIO->rxf[sm_Capture], transferCount, false); //Configure the channel dma_channel_configure(dmaPingPong0, &dmaPingPong0Config, captureBuffer, &capturePIO->rxf[sm_Capture], transferCount, true); } void stopCapture() { if(!captureFinished) { uint32_t int_status = save_and_disable_interrupts(); if(lastCaptureType == CAPTURE_TYPE_SIMPLE) simple_capture_completed(); else if(lastCaptureType == CAPTURE_TYPE_COMPLEX) complex_capture_completed(); else if(lastCaptureType == CAPTURE_TYPE_FAST) fast_capture_completed(); restore_interrupts(int_status); } } bool startCaptureFast(uint32_t freq, uint32_t preLength, uint32_t postLength, const uint8_t* capturePins, uint8_t capturePinCount, uint8_t triggerPinBase, uint8_t triggerPinCount, uint16_t triggerValue, CHANNEL_MODE captureMode) { //ABOUT THE FAST TRIGGER // //The fast trigger is an evolution of the complex trigger. //Like the complex trigger this is a sepparate program that checks for a pattern to trigger the capture program second stage. // //The main difference is the maximum length of the pattern to match and the sampling speed. This fast trigger //can only use a pattern up to 5 bits, but it captures at maximum speed of 100Msps (it could even sample up to 200Mhz but to match the //maximum speed of the sampling it is limited to 100Msps). //To achieve this the program occupies all 32 instructions of a PIO module, this is basically a jump table, each //instruction moves the pin values to the program counter except for the ones that match the pattern, which activate the //trigger pin using the side pins and create an infinite loop jumping to itself (basically a JMP currentpc SIDE 1). // //This solves the speed and latency problem, the speed reaches 100Msps and the latency is reduced to a maximum of 2 cycles, but //still can glitch on low speeds and also occupies a complete PIO module (but we have one unused, so its not a problem) int maxSamples; switch(captureMode) { case MODE_8_CHANNEL: maxSamples = 131072; break; case MODE_16_CHANNEL: maxSamples = 65536; break; case MODE_24_CHANNEL: maxSamples = 32768; break; } //Too many samples requested? if(preLength + postLength >= maxSamples) return false; //Frequency too high? if(freq > 100000000) return false; //Incorrect pin count? if(capturePinCount < 0 || capturePinCount > 24) return false; //Bad trigger? if(triggerPinBase > 15 || triggerPinCount > 5 || triggerPinCount < 1 || triggerPinCount + triggerPinBase > 16) return false; //Clear capture buffer (to avoid sending bad data if the trigger happens before the presamples are filled) memset(captureBuffer, 0, sizeof(captureBuffer)); //Store info about the capture lastPreSize = preLength; lastPostSize = postLength; lastCapturePinCount = capturePinCount; lastCaptureComplexFast = true; lastCaptureMode = captureMode; //Map channels to pins for(uint8_t i = 0; i < capturePinCount; i++) lastCapturePins[i] = pinMap[capturePins[i]]; //Store trigger info triggerPinBase = pinMap[triggerPinBase]; lastTriggerPinBase = triggerPinBase; //Calculate clock divider based on frequency, it generates a clock 2x faster than the capture freequency float clockDiv = (float)clock_get_hz(clk_sys) / (float)(freq * 2); //Store the PIO units and clear program memory capturePIO = pio1; //Cannot clear it in PIO1 because the W uses PIO1 to transfer data triggerPIO = pio0; pio_clear_instruction_memory(triggerPIO); //Configure 24 + 2 IO's to be used by the PIO (24 channels + 2 trigger pins) pio_gpio_init(triggerPIO, 0); pio_gpio_init(capturePIO, 1); for(uint8_t i = 0; i < 24; i++) pio_gpio_init(capturePIO, pinMap[i]); //Configure capture SM sm_Capture = pio_claim_unused_sm(capturePIO, true); pio_sm_clear_fifos(capturePIO, sm_Capture); pio_sm_restart(capturePIO, sm_Capture); captureOffset = pio_add_program(capturePIO, &FAST_CAPTURE_program); //Modified for the W for(int i = 0; i < 24; i++) pio_sm_set_consecutive_pindirs(capturePIO, sm_Capture, pinMap[i], 1, false); //Configure state machines pio_sm_config smConfig = FAST_CAPTURE_program_get_default_config(captureOffset); //Inputs start at pin 2 sm_config_set_in_pins(&smConfig, 2); //Set clock to 2x required frequency sm_config_set_clkdiv(&smConfig, clockDiv); //Autopush per 29 bits sm_config_set_in_shift(&smConfig, false, true, 29); //Configure fast trigger pin (pin 1) as JMP pin. sm_config_set_jmp_pin(&smConfig, 1); //Configure interrupt 0 pio_interrupt_clear (capturePIO, 0); irq_set_enabled(pio_get_dreq(capturePIO, sm_Capture, false), true); //Initialize state machine pio_sm_init(capturePIO, sm_Capture, captureOffset, &smConfig); //Configure trigger SM sm_Trigger = pio_claim_unused_sm(triggerPIO, true); pio_sm_clear_fifos(triggerPIO, sm_Trigger); pio_sm_restart(triggerPIO, sm_Trigger); //Create trigger program uint8_t triggerFirstInstruction = create_fast_trigger_program(triggerValue, triggerPinCount); //Configure trigger state machine triggerOffset = pio_add_program(triggerPIO, &FAST_TRIGGER_program); pio_sm_set_consecutive_pindirs(triggerPIO, sm_Trigger, 0, 1, true); //Pin 0 as output (connects to Pin 1, to trigger capture) pio_sm_set_consecutive_pindirs(triggerPIO, sm_Trigger, triggerPinBase, triggerPinCount, false); //Trigger pins start at triggerPinBase smConfig = FAST_TRIGGER_program_get_default_config(triggerOffset); sm_config_set_in_pins(&smConfig, triggerPinBase); //Trigger input starts at pin base sm_config_set_set_pins(&smConfig, 0, 1); //Trigger output is a set pin sm_config_set_sideset_pins(&smConfig, 0); //Trigger output is a side pin sm_config_set_clkdiv(&smConfig, 1); //Trigger always runs at max speed //Configure DMA's configureCaptureDMAs(captureMode); //Enable capture state machine pio_sm_set_enabled(capturePIO, sm_Capture, true); //Write capture length to post program pio_sm_put_blocking(capturePIO, sm_Capture, postLength - 1); //Initialize trigger state machine pio_sm_init(triggerPIO, sm_Trigger, triggerOffset, &smConfig); //Enable trigger state machine pio_sm_set_enabled(triggerPIO, sm_Trigger, true); //Finally clear capture status and process flags captureFinished = false; captureProcessed = false; lastCaptureType = CAPTURE_TYPE_FAST; //We're done return true; } bool startCaptureComplex(uint32_t freq, uint32_t preLength, uint32_t postLength, const uint8_t* capturePins, uint8_t capturePinCount, uint8_t triggerPinBase, uint8_t triggerPinCount, uint16_t triggerValue, CHANNEL_MODE captureMode) { //ABOUT THE COMPLEX TRIGGER // //The complex trigger is a hack to achieve the maximum speed in the capture program. //To get to 100Msps with a 200Mhz clock each capture must be excuted in two instructions. For this the basic //capture programs (the positive and negative ones) use the JMP PIN instruction, this redirects the program flow based in the //state of a pin, so with an IN instruction and a JMP instruction we can create a loop that captures data until the trigger pin //is in the correct edge and then jumps to another subroutine that captures until the post-trigger samples are met. // //Unfortunately there is no way to jump to a subroutine based in the status of more than one pin, you can jump based in the //comparison of the scratch registers, but this requires more than one instruction to prepare the data. //So, what I have implemented here is an asynchronouss trigger, a second state machine running at máximum speed checks if the trigger //condition is met and then notifies to the first state machine. But... there is no way to notify of something between state machines //except for interrupts, and interrupts blocks the code execution (you WAIT for the interrupt) so this is not viable, so we use a hack, we //interconnect two pins (GPIO0 and GPIO1), one is an output from the trigger state machine and the other is the JMP PIN for the capture //state machine. When the trigger condition is met the output pin is set to 1 so the JMP PIN pin receives this signal and we can keep //our capture program to use two instructions. //This carries some limitations, the trigger can only work up to 66Msps but the capture can go up to 100Msps as they are independent. //Also, as the trigger always runs at maximum speed there may happen a glitch in the trigger signal for lower capture speeds, the //condition may be met but for less time than a capture cycle, so the capture machine will not sample this trigger condition. //Finally the trigger also has some cycles of delay, 3 instructions plus 2 cycles of propagation to the ISR, so a maximum of //25ns of delay can happen. int maxSamples; switch(captureMode) { case MODE_8_CHANNEL: maxSamples = 131072; break; case MODE_16_CHANNEL: maxSamples = 65536; break; case MODE_24_CHANNEL: maxSamples = 32768; break; } //Too many samples requested? if(preLength + postLength >= maxSamples) return false; //Frequency too high? if(freq > 100000000) return false; //Incorrect pin count? if(capturePinCount < 0 || capturePinCount > 24) return false; //Bad trigger? if(triggerPinBase > 15 || triggerPinCount > 16 || triggerPinCount < 1 || triggerPinCount + triggerPinBase > 16) return false; //Clear capture buffer (to avoid sending bad data if the trigger happens before the presamples are filled) memset(captureBuffer, 0, sizeof(captureBuffer)); //Store info about the capture lastPreSize = preLength; lastPostSize = postLength; lastCapturePinCount = capturePinCount; lastCaptureComplexFast = true; lastCaptureMode = captureMode; //Map channels to pins for(uint8_t i = 0; i < capturePinCount; i++) lastCapturePins[i] = pinMap[capturePins[i]]; //Store trigger info triggerPinBase = pinMap[triggerPinBase]; lastTriggerPinBase = triggerPinBase; //Calculate clock divider based on frequency, it generates a clock 2x faster than the capture freequency float clockDiv = (float)clock_get_hz(clk_sys) / (float)(freq * 2); //Store the PIO unit and clear program memory capturePIO = pio0; pio_clear_instruction_memory(capturePIO); //Configure 24 + 2 IO's to be used by the PIO (24 channels + 2 trigger pins) pio_gpio_init(capturePIO, 0); pio_gpio_init(capturePIO, 1); for(uint8_t i = 0; i < 24; i++) pio_gpio_init(capturePIO, pinMap[i]); //Configure capture SM sm_Capture = pio_claim_unused_sm(capturePIO, true); pio_sm_clear_fifos(capturePIO, sm_Capture); pio_sm_restart(capturePIO, sm_Capture); captureOffset = pio_add_program(capturePIO, &COMPLEX_CAPTURE_program); for(int i = 0; i < 24; i++) pio_sm_set_consecutive_pindirs(capturePIO, sm_Capture, pinMap[i], 1, false); //Configure state machines pio_sm_config smConfig = COMPLEX_CAPTURE_program_get_default_config(captureOffset); //Inputs start at pin 2 sm_config_set_in_pins(&smConfig, 2); //Set clock to 2x required frequency sm_config_set_clkdiv(&smConfig, clockDiv); //Autopush per 29 bits sm_config_set_in_shift(&smConfig, false, true, 29); //Configure comples trigger pin (pin 1) as JMP pin. sm_config_set_jmp_pin(&smConfig, 1); //Configure interrupt 0 pio_interrupt_clear (capturePIO, 0); pio_set_irq0_source_enabled(capturePIO, pis_interrupt0, true); irq_set_exclusive_handler(PIO0_IRQ_0, complex_capture_completed); irq_set_enabled(PIO0_IRQ_0, true); irq_set_enabled(pio_get_dreq(capturePIO, sm_Capture, false), true); //Initialize state machine pio_sm_init(capturePIO, sm_Capture, captureOffset, &smConfig); //Configure trigger SM sm_Trigger = pio_claim_unused_sm(capturePIO, true); pio_sm_clear_fifos(capturePIO, sm_Trigger); pio_sm_restart(capturePIO, sm_Trigger); //Modify trigger program to use the correct pins COMPLEX_TRIGGER_program_instructions[5] = 0x6040 | triggerPinCount; //Configure trigger state machine triggerOffset = pio_add_program(capturePIO, &COMPLEX_TRIGGER_program); pio_sm_set_consecutive_pindirs(capturePIO, sm_Trigger, 0, 1, true); //Pin 0 as output (connects to Pin 1, to trigger capture) pio_sm_set_consecutive_pindirs(capturePIO, sm_Trigger, triggerPinBase, triggerPinCount, false); //Trigger pins start at triggerPinBase smConfig = COMPLEX_TRIGGER_program_get_default_config(triggerOffset); sm_config_set_in_pins(&smConfig, triggerPinBase); //Trigger input starts at pin base sm_config_set_set_pins(&smConfig, 0, 1); //Trigger output is a set pin sm_config_set_clkdiv(&smConfig, 1); //Trigger always runs at max speed sm_config_set_in_shift(&smConfig, false, false, 0); //Trigger shifts left to right //Initialize trigger state machine pio_sm_init(capturePIO, sm_Trigger, triggerOffset, &smConfig); //Init trigger //Configure DMA's configureCaptureDMAs(captureMode); //Enable capture state machine pio_sm_set_enabled(capturePIO, sm_Capture, true); //Write capture length to post program pio_sm_put_blocking(capturePIO, sm_Capture, postLength - 1); //Enable trigger state machine pio_sm_set_enabled(capturePIO, sm_Trigger, true); //Write trigger value to trigger program pio_sm_put_blocking(capturePIO, sm_Trigger, triggerValue); //Finally clear capture status and process flags captureFinished = false; captureProcessed = false; lastCaptureType = CAPTURE_TYPE_COMPLEX; //We're done return true; } bool startCaptureSimple(uint32_t freq, uint32_t preLength, uint32_t postLength, const uint8_t* capturePins, uint8_t capturePinCount, uint8_t triggerPin, bool invertTrigger, CHANNEL_MODE captureMode) { int maxSamples; switch(captureMode) { case MODE_8_CHANNEL: maxSamples = 131072; break; case MODE_16_CHANNEL: maxSamples = 65536; break; case MODE_24_CHANNEL: maxSamples = 32768; break; } //Too many samples requested? if(preLength + postLength >= maxSamples) return false; //Frequency too high? if(freq > 100000000) return false; //Incorrect pin count? if(capturePinCount < 0 || capturePinCount > 24) return false; //Incorrect trigger pin? if(triggerPin < 0 || triggerPin > 24) return false; //Clear capture buffer (to avoid sending bad data if the trigger happens before the presamples are filled) memset(captureBuffer, 0, sizeof(captureBuffer)); //Store info about the capture lastPreSize = preLength; lastPostSize = postLength; lastCapturePinCount = capturePinCount; lastTriggerInverted = invertTrigger; lastCaptureComplexFast = false; lastCaptureMode = captureMode; //Map channels to pins for(uint8_t i = 0; i < capturePinCount; i++) lastCapturePins[i] = pinMap[capturePins[i]]; //Store trigger info triggerPin = pinMap[triggerPin]; lastTriggerPin = triggerPin; //Calculate clock divider based on frequency, it generates a clock 2x faster than the capture freequency float clockDiv = (float)clock_get_hz(clk_sys) / (float)(freq * 2); //Store the PIO unit and clear program memory capturePIO = pio0; pio_clear_instruction_memory(capturePIO); //Configure capture SM sm_Capture = pio_claim_unused_sm(capturePIO, true); pio_sm_clear_fifos(capturePIO, sm_Capture); pio_sm_restart(capturePIO, sm_Capture); //Load correct program, depending on the trigger edge if(invertTrigger) captureOffset = pio_add_program(capturePIO, &NEGATIVE_CAPTURE_program); else captureOffset = pio_add_program(capturePIO, &POSITIVE_CAPTURE_program); //Configure capture pins for(int i = 0; i < 24; i++) pio_sm_set_consecutive_pindirs(capturePIO, sm_Capture, pinMap[i], 1, false); for(uint8_t i = 0; i < 24; i++) pio_gpio_init(capturePIO, pinMap[i]); //Configure trigger pin pio_sm_set_consecutive_pindirs(capturePIO, sm_Capture, triggerPin, 1, false); pio_gpio_init(capturePIO, triggerPin); //Configure state machines pio_sm_config smConfig = invertTrigger? NEGATIVE_CAPTURE_program_get_default_config(captureOffset): POSITIVE_CAPTURE_program_get_default_config(captureOffset); //All pins are inputs sm_config_set_in_pins(&smConfig, 2); //Set clock to 2x required frequency sm_config_set_clkdiv(&smConfig, clockDiv); //Autopush per dword sm_config_set_in_shift(&smConfig, true, true, 0); //Configure trigger pin as JMP pin. sm_config_set_jmp_pin(&smConfig, triggerPin); //Configure interupt 0 pio_interrupt_clear (capturePIO, 0); pio_set_irq0_source_enabled(capturePIO, pis_interrupt0, true); irq_set_exclusive_handler(PIO0_IRQ_0, simple_capture_completed); irq_set_enabled(PIO0_IRQ_0, true); irq_set_enabled(pio_get_dreq(capturePIO, sm_Capture, false), true); //Initialize state machine pio_sm_init(capturePIO, sm_Capture, captureOffset, &smConfig); irq_clear(pio_get_dreq(capturePIO, sm_Capture, false)); //Configure DMA's configureCaptureDMAs(captureMode); //Enabl state machine pio_sm_set_enabled(capturePIO, sm_Capture, true); //Write capture length to post program to start the capture process pio_sm_put_blocking(capturePIO, sm_Capture, postLength - 1); //Finally clear capture status, process flags and capture type captureFinished = false; captureProcessed = false; lastCaptureType = CAPTURE_TYPE_SIMPLE; //We're done return true; } bool IsCapturing() { //If you need an explanation of this, you're a fool. :P return !captureFinished; } uint8_t* GetBuffer(uint32_t* bufferSize, uint32_t* firstSample, CHANNEL_MODE* captureMode) { //If we don't have processed the buffer... if(!captureProcessed) { int maxSize; switch(lastCaptureMode) { case MODE_8_CHANNEL: maxSize = 131072; break; case MODE_16_CHANNEL: maxSize = 65536; break; case MODE_24_CHANNEL: maxSize = 32768; break; } //Calculate start position if(lastTail < lastPreSize + lastPostSize - 1) lastStartPosition = maxSize - ((lastPreSize + lastPostSize) - (lastTail - 1)); else lastStartPosition = lastTail - (lastPreSize + lastPostSize) + 1; uint32_t currentPos = lastStartPosition; switch(lastCaptureMode) { case MODE_24_CHANNEL: { uint32_t oldValue; uint32_t newValue; uint32_t* buffer = (uint32_t*)captureBuffer; //Sort channels //(reorder captured bits based on the channels requested) for(int buc = 0; buc < lastPreSize + lastPostSize; buc++) { oldValue = buffer[currentPos]; //Store current value newValue = 0; //New value for(int pin = 0; pin < lastCapturePinCount; pin++) //For each captured channel... newValue |= (oldValue & (1 << (lastCapturePins[pin] - 2))) >> ((lastCapturePins[pin] - 2) - pin); //Store its value in the correct bit //Update value in the buffer buffer[currentPos++] = newValue; //If we reached the end of the buffer, wrap around if(currentPos >= maxSize) currentPos = 0; } } break; case MODE_16_CHANNEL: { uint16_t oldValue; uint16_t newValue; uint16_t* buffer = (uint16_t*)captureBuffer; //Sort channels //(reorder captured bits based on the channels requested) for(int buc = 0; buc < lastPreSize + lastPostSize; buc++) { oldValue = buffer[currentPos]; //Store current value newValue = 0; //New value for(int pin = 0; pin < lastCapturePinCount; pin++) //For each captured channel... newValue |= (oldValue & (1 << (lastCapturePins[pin] - 2))) >> ((lastCapturePins[pin] - 2) - pin); //Store its value in the correct bit //Update value in the buffer buffer[currentPos++] = newValue; //If we reached the end of the buffer, wrap around if(currentPos >= maxSize) currentPos = 0; } } break; case MODE_8_CHANNEL: { uint8_t oldValue; uint8_t newValue; uint8_t* buffer = (uint8_t*)captureBuffer; //Sort channels //(reorder captured bits based on the channels requested) for(int buc = 0; buc < lastPreSize + lastPostSize; buc++) { oldValue = buffer[currentPos]; //Store current value newValue = 0; //New value for(int pin = 0; pin < lastCapturePinCount; pin++) //For each captured channel... newValue |= (oldValue & (1 << (lastCapturePins[pin] - 2))) >> ((lastCapturePins[pin] - 2) - pin); //Store its value in the correct bit //Update value in the buffer buffer[currentPos++] = newValue; //If we reached the end of the buffer, wrap around if(currentPos >= maxSize) currentPos = 0; } } break; } captureProcessed = true; } //Return data *captureMode = lastCaptureMode; *bufferSize = lastPreSize + lastPostSize; *firstSample = lastStartPosition; return captureBuffer; } %}