Freescale Semiconductor MPC5553 - IEEE‚ 1149.1 (JTAG) RD;WR Sequences

MPC5553/MPC5554 Microcontroller Reference Manual, Rev. 5
Freescale Semiconductor 25-69
25.11.17 IEEE 1149.1 (JTAG) RD/WR Sequences
This section contains example JTAG/OnCE sequences used to access resources.
25.11.17.1JTAG Sequence for Accessing Internal Nexus Registers
25.11.17.2 JTAG Sequence for Read Access of Memory-Mapped Resources
Table 25-42. Accessing Internal Nexus3 Registers via JTAG/OnCE
Step # TMS Pin Description
11IDLE  SELECT-DR_SCAN
2 0 SELECT-DR_SCAN  CAPTURE-DR (Nexus command register value loaded in shifter)
3 0 CAPTURE-DR  SHIFT-DR
4 0 (7) TCK clocks issued to shift in direction (rd/wr) bit and first 6 bits of Nexus reg. addr.
5 1 SHIFT-DR  EXIT1-DR (7th bit of Nexus reg. shifted in)
6 1 EXIT1-DR  UPDATE-DR (Nexus shifter is transferred to Nexus command register)
7 1 UPDATE-DR  SELECT-DR_SCAN
8 0 SELECT-DR_SCAN  CAPTURE-DR (Register value is transferred to Nexus shifter)
9 0 CAPTURE-DR  SHIFT-DR
10 0 (31) TCK clocks issued to transfer register value to TDO pin while shifting in TDI value
11 1 SHIFT-DR  EXIT1-DR (msb of value is shifted in/out of shifter)
12 1 EXIT1-DR  UPDATE -DR (if access is write, shifter is transferred to register)
13 0 UPDATE-DR RUN-TEST/IDLE (transfer complete - Nexus controller to reg. select state)
Table 25-43. Accessing Memory-Mapped Resources (Reads)
Step # TCLK clocks Description
1 13 Nexus Command = write to read/write access address register (RWA)
2 37 Write RWA (initialize starting read address—data input on TDI)
3 13 Nexus Command = write to read/write control/status register (RWCS)
4 37 Write RWCS (initialize read access mode and CNT value—data input on TDI)
5 — Wait for falling edge of RDY pin
6 13 Nexus Command = read read/write access data register (RWD)
7 37 Read RWD (data output on TDO)
8 — If CNT > 0, go back to Step #5