Chapter 36 Nexus Development Interface (NDI)
MPC5602P Microcontroller Reference Manual, Rev. 4
918
Freescale Semiconductor
provides a list of access requirements for OnCE registers.
Table 36-14. OnCE Register Access Requirements
Register
Name
Access Requirements
Requires
jd_en_once to
be asserted
Requires
DBCR0
[EDM] = 1
Requires
m_clk active
for Write
Access
Requires
CPU to be
halted
for Read
Access
Requires
CPU to be
halted
for Write
Access
Enable_OnCE
N
N
N
N
—
Bypass
N
N
N
N
N
CPUSCR
Y
Y
Y
Y
Y
DAC1
Y
Y
Y
N
1
1
Writes to these registers while the CPU is running may have unpredictable results due to the pipelined nature of
operation, and the fact that updates are not synchronized to a particular clock, instruction, or bus cycle boundary,
therefore it is strongly recommended to ensure the processor is first placed into debug mode before updates to
these registers are performed.
DAC2
Y
Y
Y
N
DBCR0
2
2
DBCR0
EDM
access only requires
jd_en_once
asserted.
Y
Y
Y
N
DBCR1
Y
Y
Y
N
DBCR2
Y
Y
Y
N
DBCR4
Y
Y
Y
N
DBERC0
Y
N
Y
N
DBSR
Y
Y
Y
N
3
3
Reads of these registers while the CPU is running may not give data that is self-consistent due to synchronization
across clock domains.
IAC1–4
Y
Y
Y
N
JTAG ID
4
4
Read-only.
N
N
—
N
—
OCR
Y
N
N
N
N
OSR
5
5
Read-only, accessed by scanning out IR while
jd_en_once
is asserted.
Y
N
—
N
—
Cache Debug Access
Control
(CDACNTL)
6,7
6
Not present on Z0Hn2p
Y
N
Y
Y
Y
Cache Debug Access
Data
(CDADATA)
Y
N
Y
Y
Y
External GPRs
Y
N
N
N
N