PXN20RM Datasheet, PDF (1219/1376 Pages) Freescale Semiconductor, Inc – PXN20 Microcontroller

Step #
9
10
11
12
13
Nexus Development Interface (NDI)
Table 36-41. Accessing Internal Nexus3 Registers via JTAG/OnCE (continued)
TMS Pin
0
0
1
1
0
Description
CAPTURE-DR  SHIFT-DR
(31) TCK clocks issued to transfer register value to TDO pin while shifting in TDI value
SHIFT-DR  EXIT1-DR (MSB of value is shifted in/out of shifter)
EXIT1-DR  UPDATE -DR (if access is write, shifter is transferred to register)
UPDATE-DR  RUN-TEST/IDLE (transfer complete - Nexus controller to reg. select state)
36.6.10.8.2 JTAG Sequence for Read Access of Memory-Mapped Resources
Table 36-42. Accessing Memory-Mapped Resources (Reads)
Step #
1
2
3
4
5
6
7
TCLK clocks
13
37
13
37
13
37
—
Description
Nexus Command = write to read/write access address register (RWA)
Write RWA (initialize starting read address—data input on TDI)
Nexus Command = write to read/write control/status register (RWCS)
Write RWCS (initialize read access mode and CNT value—data input on TDI)
Nexus Command = read read/write access data register (RWD)
Read RWD (data output on TDO)
If CNT > 0, go back to Step #5
36.6.10.8.3 JTAG Sequence for Write Access of Memory-Mapped Resources
Table 36-43. Accessing Memory-Mapped Resources (Writes)
Step #
1
2
3
4
5
6
7
TCLK clocks
13
37
13
37
13
37
—
Description
Nexus Command = write to read/write access control/status register (RWCS)
Write RWCS (initialize write access mode and CNT value—data input on TDI)
Nexus Command = write to read/write address register (RWA)
Write RWA (initialize starting write address—data input on TDI)
Nexus Command = read read/write access data register (RWD)
Write RWD (data output on TDO)
If CNT > 0, go back to Step #5
Freescale Semiconductor
PXN20 Microcontroller Reference Manual, Rev. 1
36-69