Merge pull request #95 from iddq/master

fix jtag_read_reg and jtag_write_reg functions according to the docum…
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Daniel Beer 2020-06-02 09:22:38 +12:00 committed by GitHub
commit e65bc6910a
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1 changed files with 15 additions and 17 deletions

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@ -30,6 +30,8 @@
* jtag_write_reg corrected
* 2015-02-21 jtag_set_breakpoint added Peter Bägel (DF5EQ)
* jtag_cpu_state added
* 2020-06-01 jtag_read_reg corrected Gabor Mayer (HG5OAP)
* jtag_write_reg corrected
*/
#include <stdlib.h>
@ -953,23 +955,23 @@ address_t jtag_read_reg(struct jtdev *p, int reg)
{
unsigned int value;
/* Set CPU into instruction fetch mode */
jtag_set_instruction_fetch(p);
/* CPU controls RW & BYTE */
jtag_ir_shift(p, IR_CNTRL_SIG_16BIT);
jtag_dr_shift_16(p, 0x3401);
/* Set CPU into instruction fetch mode */
jtag_set_instruction_fetch(p);
jtag_ir_shift(p, IR_DATA_16BIT);
/* "jmp $-4" instruction */
/* PC - 4 -> PC */
/* needs 2 clock cycles */
jtag_dr_shift_16(p, 0x3ffd);
jtag_tclk_set(p);
jtag_tclk_clr(p);
jtag_tclk_set(p);
jtag_tclk_clr(p);
jtag_tclk_set(p);
/* "mov Rn,&0x01fe" instruction
* Rn -> &0x01fe
@ -979,15 +981,15 @@ address_t jtag_read_reg(struct jtdev *p, int reg)
* the registers value is placed on the databus
*/
jtag_dr_shift_16(p, 0x4082 | (((unsigned int)reg << 8) & 0x0f00) );
jtag_tclk_set(p);
jtag_tclk_clr(p);
jtag_tclk_set(p);
jtag_dr_shift_16(p, 0x01fe);
jtag_tclk_set(p);
jtag_tclk_clr(p);
jtag_tclk_set(p);
jtag_tclk_clr(p);
jtag_tclk_set(p);
jtag_tclk_clr(p);
jtag_tclk_set(p);
/* Read databus which contains the registers value */
jtag_ir_shift(p, IR_DATA_CAPTURE);
@ -997,8 +999,6 @@ address_t jtag_read_reg(struct jtdev *p, int reg)
jtag_ir_shift(p, IR_CNTRL_SIG_16BIT);
jtag_dr_shift_16(p, 0x2401);
jtag_tclk_set(p);
/* Return value read from register */
return value;
}
@ -1006,23 +1006,23 @@ address_t jtag_read_reg(struct jtdev *p, int reg)
/* Writes a value into a register of the target CPU */
void jtag_write_reg(struct jtdev *p, int reg, address_t value)
{
/* Set CPU into instruction fetch mode */
jtag_set_instruction_fetch(p);
/* CPU controls RW & BYTE */
jtag_ir_shift(p, IR_CNTRL_SIG_16BIT);
jtag_dr_shift_16(p, 0x3401);
/* Set CPU into instruction fetch mode */
jtag_set_instruction_fetch(p);
jtag_ir_shift(p, IR_DATA_16BIT);
/* "jmp $-4" instruction */
/* PC - 4 -> PC */
/* needs 4 clock cycles */
jtag_dr_shift_16(p, 0x3ffd);
jtag_tclk_set(p);
jtag_tclk_clr(p);
jtag_tclk_set(p);
jtag_tclk_clr(p);
jtag_tclk_set(p);
/* "mov #value,Rn" instruction
* value -> Rn
@ -1030,17 +1030,15 @@ void jtag_write_reg(struct jtdev *p, int reg, address_t value)
* needs 2 clock cycles
*/
jtag_dr_shift_16(p, 0x4030 | (reg & 0x000f) );
jtag_tclk_set(p);
jtag_tclk_clr(p);
jtag_tclk_set(p);
jtag_dr_shift_16(p, value);
jtag_tclk_set(p);
jtag_tclk_clr(p);
jtag_tclk_set(p);
/* JTAG controls RW & BYTE */
jtag_ir_shift(p, IR_CNTRL_SIG_16BIT);
jtag_dr_shift_16(p, 0x2401);
jtag_tclk_set(p);
}
/*----------------------------------------------------------------------------*/