From c7a17b8466d655f024d62fd106701e5042fb7ccc Mon Sep 17 00:00:00 2001 From: Ali Lown Date: Sun, 3 Apr 2011 22:16:51 +0100 Subject: Buffering for up to 64 bytes in USB Blaster. Uses a global buffer. Add self to acknowledgements. --- src/jtag/drivers/usb_blaster.c | 50 ++++++++++++++++++++++++++++++++---------- 1 file changed, 38 insertions(+), 12 deletions(-) (limited to 'src/jtag') diff --git a/src/jtag/drivers/usb_blaster.c b/src/jtag/drivers/usb_blaster.c index 1e8aa8d9..68867adf 100644 --- a/src/jtag/drivers/usb_blaster.c +++ b/src/jtag/drivers/usb_blaster.c @@ -4,6 +4,10 @@ * (http://www.ixo.de/info/usb_jtag/). * * Some updates by Anthony Liu (2006). * * Minor updates and cleanup by Catalin Patulea (2009). * + * Speed updates by Ali Lown (2011). * + * * + * Copyright (C) 2011 Ali Lown * + * ali@lown.me.uk * * * * Copyright (C) 2009 Catalin Patulea * * cat@vv.carleton.ca * @@ -104,8 +108,12 @@ static char *usb_blaster_device_desc; static uint16_t usb_blaster_vid = 0x09fb; /* Altera */ static uint16_t usb_blaster_pid = 0x6001; /* USB-Blaster */ -/* last output byte in simple bit banging mode */ +/* last output byte in simple bit banging (legacy) mode */ static uint8_t out_value; +/* global output buffer for bit banging */ +#define BUF_LEN 64 //Size of EP1 +static uint8_t out_buffer[BUF_LEN]; +static uint16_t out_count = 0; #if BUILD_USB_BLASTER_FTD2XX == 1 static FT_HANDLE ftdih; @@ -195,8 +203,7 @@ usb_blaster_buf_read(uint8_t *buf, unsigned size, uint32_t *bytes_read) } /* The following code doesn't fully utilize the possibilities of the - * USB-Blaster. It writes one byte per JTAG pin state change at a time; it - * doesn't even try to buffer data up to the maximum packet size of 64 bytes. + * USB-Blaster. It only buffers data up to the maximum packet size of 64 bytes. * * Actually, the USB-Blaster offers a byte-shift mode to transmit up to 504 data * bits (bidirectional) in a single USB packet. A header byte has to be sent as @@ -225,8 +232,8 @@ usb_blaster_buf_read(uint8_t *buf, unsigned size, uint32_t *bytes_read) * Bit 0 (0x01): TCK Output. * * For transmitting a single data bit, you need to write two bytes. Up to 64 - * bytes can be combined in a single USB packet (but this is not done in the - * code below). It isn't possible to read a data without transmitting data. + * bytes can be combined in a single USB packet. + * It isn't possible to read a data without transmitting data. */ #define TCK (1 << 0) @@ -241,10 +248,22 @@ usb_blaster_buf_read(uint8_t *buf, unsigned size, uint32_t *bytes_read) #define READ_TDO (1 << 0) -static void usb_blaster_write_data(void) +static void usb_blaster_write_databuffer(uint8_t* buf, uint16_t len) { uint32_t bytes_written; - usb_blaster_buf_write(&out_value, 1, &bytes_written); + usb_blaster_buf_write(buf, len, &bytes_written); + out_count = 0; +#ifdef _DEBUG_JTAG_IO_ + LOG_DEBUG("---- WROTE %d",bytes_written); +#endif +} + +static void usb_blaster_addtowritebuffer(uint8_t value, bool forcewrite) +{ + out_buffer[out_count] = value; + out_count += 1; + if(out_count == BUF_LEN || forcewrite) + usb_blaster_write_databuffer(out_buffer, out_count); } static int usb_blaster_read_data(void) @@ -253,8 +272,11 @@ static int usb_blaster_read_data(void) uint8_t buf[1]; uint32_t bytes_read; + if(out_count > 0) + usb_blaster_write_databuffer(out_buffer, out_count); + out_value |= READ; - usb_blaster_write_data(); + usb_blaster_addtowritebuffer(out_value, true); out_value &= ~READ; status = usb_blaster_buf_read(buf, 1, &bytes_read); @@ -277,7 +299,7 @@ static void usb_blaster_write(int tck, int tms, int tdi) if (tdi) out_value |= TDI; - usb_blaster_write_data(); + usb_blaster_addtowritebuffer(out_value, false); } static int usb_blaster_speed(int speed) @@ -312,7 +334,8 @@ static void usb_blaster_blink(int state) out_value = 0x00; if(state) out_value |= LED; - usb_blaster_write_data(); + + usb_blaster_addtowritebuffer(out_value, true); } static struct bitbang_interface usb_blaster_bitbang = { @@ -478,6 +501,9 @@ static int usb_blaster_init(void) static int usb_blaster_quit(void) { + if(out_count > 0) + usb_blaster_write_databuffer(out_buffer, out_count); + #if BUILD_USB_BLASTER_FTD2XX == 1 FT_STATUS status; @@ -543,12 +569,12 @@ COMMAND_HANDLER(usb_blaster_handle_pin_command) if (state == 0) { out_value &= ~mask; - usb_blaster_write_data(); + usb_blaster_addtowritebuffer(out_value, true); } else if (state == 1) { out_value |= mask; - usb_blaster_write_data(); + usb_blaster_addtowritebuffer(out_value, true); } else { -- cgit v1.2.3