AN2074 Freescale Semiconductor / Motorola, AN2074 Datasheet - Page 21

• Manufacturer Part Number: AN2074
• Description: DSP56300 JTAG Examples
• Manufacturer: Freescale Semiconductor / Motorola

START
JTAG_BYPASS:
3.4 IDCODE Example
The IDCODE example shows how the instruction is executed. The Select-IR scan path is selected to shift
in the IDCODE instruction by sending 0010 on
the contents of the ID Register on
The most significant byte is stored in the low byte of x:JTAG_OUT, and the lower 24 bits are stored in
x:JTAG_OUT+1 as shown in Table 8. The JTAG_EXECUTE subroutine is modified so that when 24 bits
are shifted out, they are stored in x:JTAG_OUT+1. Subsequent data is stored in x:JTAG_OUT. Table 7
describes the instructions used in Figure 12.
dc
dc
dc
dc
dc
dc
dc
dc
dc
dc
dc
dc
org
...
jsr
jsr
debug
move
jsr
rts
B3
0
0
0
0
0
0
0
1
$04
$04
$04
$04
$04
$04
$14
$14
$30
$34
$10
$00
p:$100
JTAG_RTI
JTAG_BYPASS
#JTAG_BYPASS_SEQ,r0
JTAG_EXECUTE
B2
0
0
0
1
1
1
1
1
; go to Shift DR - TDI=0
; go to Shift DR - TDI=0
; go to Shift DR - TDI=0
; go to Shift DR - TDI=0
; go to Shift DR - TDI=0
; go to Shift DR - TDI=0
; go to Shift DR - TDI=1
; go to Shift DR - TDI=1
; go to Exit DR
; go to Update DR
; go to Run-Test-Idle
; EXIT
Freescale Semiconductor, Inc.
B1
0
0
1
0
0
1
1
1
For More Information On This Product,
Table 7. IDCODE Instruction Example
B0
TDO
0
1
0
1
0
0
1
1
Go to: www.freescale.com
DSP56300 JTAG Examples
- TDI=x
. The 32-bit data is stored in x:JTAG_OUT and x:JTAG_OUT+1.
EXTEST
SAMPLE/PRELOAD
IDCODE
CLAMP
HIGHZ
ENABLE_ONCE
DEBUG_REQUEST
BYPASS
Instruction
TDI
TDO=1
TDO=0
TDO=0
TDO=0
TDO=0
TDO=0
TDO=0
TDO=1
TDO=1
. Next, the Select-DR scan path is selected to shift out
Boundary-Scan Register
Boundary-Scan Register
ID Register
Bypass
Bypass
OnCE Register
OnCE Register
Bypass
Register Selected
IDCODE Example
21