-//GoodFET JTAG Application
-//Handles basic I/O
+/*! \file jtag.c
+ \author Travis Goodspeed <travis at radiantmachines.com>
+ \brief Low-level JTAG
+*/
-//Higher level left to client application.
#include "platform.h"
#include "command.h"
#include "jtag.h"
+#define JTAG_APP
+//! Handles a monitor command.
+void jtag_handle_fn(uint8_t const app,
+ uint8_t const verb,
+ uint32_t const len);
+//! JTAG device ID.
+unsigned char jtagid=0;
-//! Set up the pins for JTAG mode.
-void jtagsetup(){
- P5DIR|=MOSI+SCK+TMS;
- P5DIR&=~MISO;
- P5OUT|=0xFFFF;
- P4DIR|=TST;
- P2DIR|=RST;
-}
-
-int savedtclk=0;
-//! Shift 8 bits in and out.
-unsigned char jtagtrans8(unsigned char byte){
- unsigned int bit;
- SAVETCLK;
- for (bit = 0; bit < 8; bit++) {
- /* write MOSI on trailing edge of previous clock */
- if (byte & 0x80)
- {SETMOSI;}
- else
- {CLRMOSI;}
- byte <<= 1;
-
- if(bit==7)
- SETTMS;//TMS high on last bit to exit.
-
- CLRTCK;
- SETTCK;
- /* read MISO on trailing edge */
- byte |= READMISO;
- }
- RESTORETCLK;
-
- // exit state
- CLRTCK;
- SETTCK;
- // update state
- CLRTMS;
- CLRTCK;
- SETTCK;
-
- return byte;
+// define the jtag app's app_t
+app_t const jtag_app = {
+
+ /* app number */
+ JTAG,
+
+ /* handle fn */
+ jtag_handle_fn,
+
+ /* name */
+ "JTAG",
+
+ /* desc */
+ "\tThe JTAG app handles basic JTAG operations such as\n"
+ "\tresetting the TAP, resetting the target, detecting\n"
+ "\tthe instruction register width, shifting bits into\n"
+ "\tboth the instruction and data registers.\n"
+};
+
+
+//! Remembers what the current JTAG state is
+enum eTAPState jtag_state = UNKNOWN;
+
+//! Returns true if we're in any of the data register states
+int in_dr()
+{
+ return (int)(jtag_state & (SELECT_DR_SCAN | CAPTURE_DR |
+ SHIFT_DR | EXIT1_DR | PAUSE_DR |
+ EXIT2_DR | UPDATE_DR));
}
-//! Shift 8 bits in and out.
-unsigned int jtagtrans16(unsigned int word){
- unsigned int bit;
- SAVETCLK;
-
- for (bit = 0; bit < 16; bit++) {
- /* write MOSI on trailing edge of previous clock */
- if (word & 0x8000)
- {SETMOSI;}
- else
- {CLRMOSI;}
- word <<= 1;
-
- if(bit==15)
- SETTMS;//TMS high on last bit to exit.
-
- CLRTCK;
- SETTCK;
- /* read MISO on trailing edge */
- word |= READMISO;
- }
- RESTORETCLK;
-
- // exit state
- CLRTCK;
- SETTCK;
- // update state
- CLRTMS;
- CLRTCK;
- SETTCK;
-
- return word;
+//! Returns true if we're in any of the instruction register states
+int in_ir()
+{
+ return (int)(jtag_state & (SELECT_IR_SCAN | CAPTURE_IR |
+ SHIFT_IR | EXIT1_IR | PAUSE_IR |
+ EXIT2_IR | UPDATE_IR));
+}
+
+//! Returns true if we're in run-test-idle state
+int in_run_test_idle()
+{
+ return (int)(jtag_state & RUN_TEST_IDLE);
+}
+
+//! Check the state
+int in_state(enum eTAPState state)
+{
+ return (int)(jtag_state & state);
+}
+
+
+//! Reset the target device
+void jtag_reset_target()
+{
+ SETRST;
+ led_toggle();
+ CLRRST;
+ led_toggle();
+}
+
+//! Clock the JTAG clock line
+void jtag_tcktock()
+{
+ CLRTCK;
+ led_toggle();
+ SETTCK;
+ led_toggle();
+}
+
+//! Goes through test-logic-reset and ends in run-test-idle
+void jtag_reset_tap()
+{
+ CLRMOSI;
+ SETTMS;
+ jtag_tcktock();
+ jtag_tcktock();
+ jtag_tcktock();
+ jtag_tcktock();
+ jtag_tcktock(); // now in Reset state
+ CLRTMS;
+ jtag_tcktock(); // now in Run-Test/Idle state
+ jtag_state = RUN_TEST_IDLE;
+}
+
+//! Set up the pins for JTAG mode.
+void jtag_setup()
+{
+ P5DIR|=MOSI+SCK+TMS;
+ P5DIR&=~MISO;
+ P4DIR|=TST;
+ P2DIR|=RST;
+ msdelay(100);
+ jtag_state = UNKNOWN;
}
//! Stop JTAG, release pins
-void jtag_stop(){
- P5OUT=0;
- P4OUT=0;
+void jtag_stop()
+{
+ P5OUT=0;
+ P4OUT=0;
}
+//! Get into Shift-IR or Shift-DR state
+void jtag_shift_register()
+{
+ // assumes we're in any state that can transition to Shift-IR or Shift-DR
+ if (!in_state(CAPTURE_DR | CAPTURE_IR | SHIFT_DR |
+ SHIFT_IR | EXIT2_DR | EXIT2_IR ))
+ {
+ debugstr("Invalid JTAG state");
+ return;
+ }
-//! Shift 16 bits of the DR.
-unsigned int jtag_dr_shift16(unsigned int in){
- // idle
- SETTMS;
- CLRTCK;
- SETTCK;
- // select DR
- CLRTMS;
- CLRTCK;
- SETTCK;
- // capture IR
- CLRTCK;
- SETTCK;
+ CLRMOSI;
+ CLRTMS;
+ jtag_tcktock();
+
+ if (in_dr())
+ jtag_state = SHIFT_DR;
+ else
+ jtag_state = SHIFT_IR;
+}
+
+//! Get into Capture-IR state
+void jtag_capture_ir()
+{
+ // assumes you're in Run-Test/Idle, Update-DR or Update-IR
+ if (!in_state(RUN_TEST_IDLE | UPDATE_DR | UPDATE_IR))
+ {
+ debugstr("Invalid JTAG state");
+ return;
+ }
- // shift DR, then idle
- return(jtagtrans16(in));
+ CLRMOSI;
+ SETTMS;
+ jtag_tcktock(); // Select-DR-Scan
+ jtag_tcktock(); // Select-IR-Scan
+ CLRTMS;
+ jtag_tcktock(); // Capture-IR
+
+ jtag_state = CAPTURE_IR;
+}
+
+//! Get into Capture-DR state
+void jtag_capture_dr()
+{
+ // assumes you're in Run-Test/Idle, Update-DR or Update-IR
+ if (!in_state(RUN_TEST_IDLE | UPDATE_DR | UPDATE_IR))
+ {
+ debugstr("Invalid JTAG state");
+ return;
+ }
+
+ CLRMOSI;
+ SETTMS;
+ jtag_tcktock(); // Select-DR-Scan
+ CLRTMS;
+ jtag_tcktock(); // Capture-IR
+
+ jtag_state = CAPTURE_DR;
}
+//! Gets back to run-test-idle without going through the test-logic-reset
+void jtag_run_test_idle()
+{
+ CLRMOSI;
+
+ if (in_state(SELECT_DR_SCAN | SELECT_IR_SCAN))
+ {
+ CLRTMS;
+ jtag_tcktock();
+ jtag_state <<= 1; //CAPTURE_DR or CAPTURE_IR
+ }
+
+ if (in_state(CAPTURE_DR | CAPTURE_IR))
+ {
+ SETTMS;
+ jtag_tcktock();
+ jtag_state <<= 2; //EXIT1_DR or EXIT1_IR
+ }
+
+ if (in_state(SHIFT_DR | SHIFT_IR))
+ {
+ SETTMS;
+ jtag_tcktock();
+ jtag_state <<= 1; //EXIT1_DR or EXIT1_IR
+ }
+
+ if (in_state(EXIT1_DR | EXIT1_IR))
+ {
+ SETTMS;
+ jtag_tcktock();
+ jtag_state <<=3; //UPDATE_DR or UPDATE_IR
+ }
+
+ if (in_state(PAUSE_DR | PAUSE_IR))
+ {
+ SETTMS;
+ jtag_tcktock();
+ jtag_state <<= 1; // EXIT2_DR or EXIT2_IR
+ }
+
+ if (in_state(EXIT2_DR | EXIT2_IR))
+ {
+ SETTMS;
+ jtag_tcktock();
+ jtag_state <<= 1; // UPDATE_DR or UPDATE_IR
+ }
+
+ if (in_state(UPDATE_DR | UPDATE_IR | TEST_LOGIC_RESET))
+ {
+ CLRTMS;
+ jtag_tcktock();
+ jtag_state = RUN_TEST_IDLE;
+ }
+}
+
+int savedtclk;
+// NOTE: important: THIS MODULE REVOLVES AROUND RETURNING TO RUNTEST/IDLE, OR
+// THE FUNCTIONAL EQUIVALENT
+//! Shift N bits over TDI/TDO. May choose LSB or MSB, and select whether to
+// terminate (TMS-high on last bit) and whether to return to RUNTEST/IDLE
+// flags should be 0 for most uses.
+// for the extreme case, flags should be (NOEND|NORETDLE|LSB)
+// other edge cases can involve a combination of those three flags
+//
+// the max bit-size that can be be shifted is 32-bits.
+// for longer shifts, use the NOEND flag (which infers NORETIDLE so the
+// additional flag is unnecessary)
+//
+// NORETIDLE is used for special cases where (as with arm) the debug
+// subsystem does not want to return to the RUN-TEST/IDLE state between
+// setting IR and DR
+uint32_t jtag_trans_n(uint32_t word,
+ uint8_t bitcount,
+ enum eTransFlags flags)
+{
+ uint8_t bit;
+ uint32_t high = (1L << (bitcount - 1));
+ uint32_t mask = high - 1;
+
+ if (!in_state(SHIFT_IR | SHIFT_DR))
+ {
+ debugstr("jtag_trans_n from invalid TAP state");
+ return 0;
+ }
+
+ SAVETCLK;
+
+ if (flags & LSB)
+ {
+ for (bit = bitcount; bit > 0; bit--)
+ {
+ /* write MOSI on trailing edge of previous clock */
+ if (word & 1)
+ {
+ SETMOSI;
+ }
+ else
+ {
+ CLRMOSI;
+ }
+ word >>= 1;
+
+ if ((bit == 1) && !(flags & NOEND))
+ SETTMS; //TMS high on last bit to exit.
+
+ jtag_tcktock();
+
+ if ((bit == 1) && !(flags & NOEND))
+ jtag_state <<= 1; // Exit1-DR or Exit1-IR
+
+ /* read MISO on trailing edge */
+ if (READMISO)
+ {
+ word += (high);
+ }
+ }
+ }
+ else
+ {
+ for (bit = bitcount; bit > 0; bit--)
+ {
+ /* write MOSI on trailing edge of previous clock */
+ if (word & high)
+ {
+ SETMOSI;
+ }
+ else
+ {
+ CLRMOSI;
+ }
+ word = (word & mask) << 1;
+
+ if ((bit==1) && !(flags & NOEND))
+ SETTMS; //TMS high on last bit to exit.
+
+ jtag_tcktock();
+
+ if ((bit == 1) && !(flags & NOEND))
+ jtag_state <<= 1; // Exit1-DR or Exit1-IR
+
+ /* read MISO on trailing edge */
+ word |= (READMISO);
+ }
+ }
+
+ //This is needed for 20-bit MSP430 chips.
+ //Might break another 20-bit chip, if one exists.
+ if(bitcount==20){
+ word = ((word << 16) | (word >> 4)) & 0x000FFFFF;
+ }
+
+ RESTORETCLK;
+
+ if (!(flags & NOEND))
+ {
+ // exit state
+ jtag_tcktock();
+
+ jtag_state <<= 3; // Update-DR or Update-IR
+
+ // update state
+ if (!(flags & NORETIDLE))
+ {
+ CLRTMS;
+ jtag_tcktock();
+
+ jtag_state = RUN_TEST_IDLE;
+ }
+ }
+
+ return word;
+}
+
+//! Detects the width of the IR register
+uint16_t jtag_detect_ir_width()
+{
+ int i;
+ uint16_t width = 0;
+
+ if (!in_run_test_idle())
+ {
+ debugstr("Not in run-test-idle state");
+ return 0;
+ }
+
+ // get to shift-ir state
+ jtag_capture_ir();
+ jtag_shift_register();
+
+ // first we shift in 1024 zeros
+ CLRMOSI;
+ for(i = 0; i < 1024; i++)
+ {
+ jtag_tcktock();
+ }
+
+ // now we'll clock in ones until we see one
+ SETMOSI;
+ for(i = 0; i < 1024; i++)
+ {
+ jtag_tcktock();
+ if(READMISO)
+ break;
+ width++;
+ }
+
+ // now get back to run-test-idle
+ jtag_run_test_idle();
+
+ return width;
+}
+
+//! Detects how many TAPs are in the JTAG chain
+uint16_t jtag_detect_chain_length()
+{
+ int i;
+ int bit;
+ uint16_t length = 0;
+
+ if (!in_run_test_idle())
+ {
+ debugstr("detect chain length must start from run-test-idle");
+ return 0;
+ }
+
+ // The standard JTAG instruction for "bypass" mode is to set all 1's in the
+ // instruction register. When in "bypass" mode, the DR acts like a 1-bit
+ // shift regiser. So we can use that to detect how many TAPs are in the
+ // chain.
+
+ // first get into shift IR mode
+ jtag_capture_ir();
+ jtag_shift_register();
+
+ // then we flood the IR chain with all 1's to put all device's DRs
+ // into bypass mode
+ CLRTMS;
+ SETMOSI;
+ for (i = 0; i < 1024; i++)
+ {
+ if (i == 1023)
+ SETTMS; // exit on last bit
+ jtag_tcktock();
+ }
+ jtag_state = EXIT1_IR;
+
+ // go to Update-IR
+ CLRMOSI;
+ jtag_tcktock();
+ jtag_state = UPDATE_IR;
+
+ // go to Shift-DR state
+ jtag_capture_dr();
+ jtag_shift_register();
+
+ // flush the DR's with zeros
+ CLRTMS;
+ CLRMOSI;
+ for (i = 0; i < 1024; i++)
+ {
+ jtag_tcktock();
+ }
+
+ // send 1's into the DRs until we see one come out the other side
+ SETMOSI;
+ for (i = 0; i < 1024; i++)
+ {
+ jtag_tcktock();
+ bit = READMISO;
+ if (bit)
+ break;
+ length++;
+ }
+
+ // now get back to run-test-idle
+ jtag_run_test_idle();
+
+ return length;
+}
+
+//! Gets device ID for specified chip in the chain
+uint32_t jtag_get_device_id(int chip)
+{
+ int i;
+ uint16_t chain_length;
+ uint32_t id = 0;
+
+ // reset everything
+ jtag_reset_tap();
+
+ // figure out how many devices are in the chain
+ chain_length = jtag_detect_chain_length();
+
+ if (chip >= chain_length)
+ {
+ debugstr("invalid part index");
+ return 0;
+ }
+
+ // reset everything again because going through test-logic-reset forces
+ // all IR's to have their manufacturer specific instruction for IDCODE
+ // and loads the DR's with the chip's ID code.
+ jtag_reset_tap();
+
+ // get into shift DR state
+ jtag_capture_dr();
+ jtag_shift_register();
+
+ // read out the 32-bit ID codes for each device
+ CLRTMS;
+ CLRMOSI;
+ for (i = 0; i < (chip + 1); i++)
+ {
+ id = jtag_trans_n(0xFFFFFFFF, 32, LSB | NOEND | NORETIDLE);
+ }
+
+ jtag_run_test_idle();
+
+ return id;
+}
+
+//! Shift 8 bits in/out of selected register
+uint8_t jtag_trans_8(uint8_t in)
+{
+ uint32_t out = jtag_trans_n((uint32_t)in, 8, MSB);
+ return (uint8_t)(0x000000FF & out);
+}
+
+//! Shift 16 bits in/out of selected register
+uint16_t jtag_trans_16(uint16_t in)
+{
+ uint32_t out = jtag_trans_n((uint32_t)in, 16, MSB);
+ return (uint16_t)(0x0000FFFF & out);
+}
//! Shift 8 bits of the IR.
-unsigned char jtag_ir_shift8(unsigned char in){
+uint8_t jtag_ir_shift_8(uint8_t in)
+{
+ /* Huseby's code, which breaks MSP430 support.
+ The code is broken because either the invalid jtag state error
+ causes the client to give up, or because it adds an extra clock edge.
+
+ if (!in_run_test_idle())
+ {
+ debugstr("Not in run-test-idle state");
+ return 0;
+ }
+
+ // get intot the right state
+ jtag_capture_ir();
+ jtag_shift_register();
+ */
+
+
+
// idle
SETTMS;
- CLRTCK;
- SETTCK;
+ jtag_tcktock();
// select DR
- CLRTCK;
- SETTCK;
+ jtag_tcktock();
// select IR
CLRTMS;
- CLRTCK;
- SETTCK;
+ jtag_tcktock();
// capture IR
- CLRTCK;
- SETTCK;
-
- // shift IR, then idle.
- return(jtagtrans8(in));
+ jtag_tcktock();
+ //jtag_state = CAPTURE_IR;
+ jtag_state = SHIFT_IR;
+ // shift IR bits
+ return jtag_trans_8(in);
+}
+
+//! Shift 16 bits of the DR.
+uint16_t jtag_dr_shift_16(uint16_t in)
+{
+
+ if (!in_run_test_idle())
+ {
+ debugstr("Not in run-test-idle state");
+ return 0;
+ }
+
+ // get intot the right state
+ jtag_capture_dr();
+ jtag_shift_register();
+
+ // shift DR, then idle
+ return jtag_trans_16(in);
}
//! Handles a monitor command.
-void jtaghandle(unsigned char app,
- unsigned char verb,
- unsigned char len){
- switch(verb){
- //START handled by specific JTAG
- case STOP:
- jtag_stop();
- txdata(app,verb,0);
- break;
- case SETUP:
- jtagsetup();
- txdata(app,verb,0);
- break;
- case JTAG_IR_SHIFT:
- cmddata[0]=jtag_ir_shift8(cmddata[0]);
- txdata(app,verb,1);
- break;
- case JTAG_DR_SHIFT:
- cmddataword[0]=jtag_dr_shift16(cmddataword[0]);
- txdata(app,verb,2);
- break;
- default:
- txdata(app,NOK,0);
- }
+void jtag_handle_fn(uint8_t const app,
+ uint8_t const verb,
+ uint32_t const len)
+{
+ switch(verb)
+ {
+ // START handled by specific JTAG
+ case STOP:
+ jtag_stop();
+ txdata(app,verb,0);
+ break;
+
+ case SETUP:
+ jtag_setup();
+ txdata(app,verb,0);
+ break;
+
+ case JTAG_IR_SHIFT:
+ cmddata[0] = jtag_ir_shift_8(cmddata[0]);
+ txdata(app,verb,1);
+ break;
+
+ case JTAG_DR_SHIFT:
+ cmddataword[0] = htons(jtag_dr_shift_16(ntohs(cmddataword[0])));
+ txdata(app,verb,2);
+ break;
+
+ case JTAG_RESET_TAP:
+ jtag_reset_tap();
+ txdata(app,verb,0);
+ break;
+
+ case JTAG_RESET_TARGET:
+ jtag_reset_tap();
+ jtag_reset_target();
+ txdata(app,verb,0);
+ break;
+
+ case JTAG_DETECT_IR_WIDTH:
+ jtag_reset_tap();
+ cmddataword[0] = htons(jtag_detect_ir_width());
+ txdata(app,verb,2);
+ break;
+
+ case JTAG_DETECT_CHAIN_LENGTH:
+ jtag_reset_tap();
+ cmddataword[0] = htons(jtag_detect_chain_length());
+ txdata(app,verb,2);
+ break;
+
+ case JTAG_GET_DEVICE_ID:
+ jtag_reset_tap();
+ cmddatalong[0] = htonl(jtag_get_device_id(ntohs(cmddataword[0])));
+ txdata(app,verb,4);
+ break;
+
+ default:
+ txdata(app,NOK,0);
+ }
}
projects / goodfet / blobdiff