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Buffering for up to 64 bytes in USB Blaster.

Uses a global buffer.
Add self to acknowledgements.
tags/v0.5.0-rc1
Ali Lown 13 years ago
committed by Øyvind Harboe
parent
commit
c7a17b8466
1 changed files with 38 additions and 12 deletions
  1. +38
    -12
      src/jtag/drivers/usb_blaster.c

+ 38
- 12
src/jtag/drivers/usb_blaster.c View File

@@ -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
{


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