Nexus3/ Module
e200z3 Power Architecture Core Reference Manual, Rev. 2
Freescale Semiconductor
10-15
10.4.4
Development Status Register (DS)
The development status registe shown in
is used to report system debug status. When debug
mode is entered or exited, or an SOC- or e200z3-defined low-power mode is entered, a debug status
message is transmitted with DS[31–25]. The external tool can read this register at any time.
10.4.5
Read/Write Access Control/Status Register (RWCS)
The read write access control/status register, shown in
, provides control for read/write access.
Read/write access provides DMA-like access to memory-mapped resources on the AHB system bus either
while the processor is halted, or during runtime. RWCS also provides read/write access status information;
see
31
30
28 27 26
25
24
0
Field DBG
LPC
LPC CHK
—
Reset
All zeros
R/W
Read–only
Number
0x4
Figure 10-7. Development Status Register (DS)
Table 10-12. DS Field Descriptions
Bits
Name
Description
31
DBG
e200z3 CPU debug mode status
0 CPU not in debug mode
1 CPU in debug mode (
jd_debug_b signal asserted)
30–28
LPS
e200z3 system low power mode status
000 Normal (run) mode
XX1 Doze mode (
p_doze signal asserted)
X1X Nap mode (
p_nap signal asserted)
1XX Sleep mode (
p_sleep signal asserted)
27–26
LPC
e200z3 CPU low power mode status
00 Normal (run) mode
01 CPU in halted state (
p_halted signal asserted)
10 CPU in stopped state (
p_stopped signal asserted)
11 CPU in Waiting state (
p_waiting
signal asserted)
25
CHK
e200z3 CPU checkstop status
0 CPU not in checkstop state
1 CPU in checkstop state (
p_chkstop signal asserted)
24–0
—
Reserved, should be cleared.