![](http://datasheet.mmic.net.cn/230000/79RC32438-200BB_datasheet_15568909/79RC32438-200BB_492.png)
IDT EJTAG System
EJTAG Processor Core Extensions
79RC32438 User Reference Manual
20 - 26
November 4, 2002
Notes
instruction sequence must be used both in the beginning of the debug handler before pending imprecise
errors are detected from Non-Debug Mode, and at the end of the debug handler before pending imprecise
errors are detected from Debug Mode. The IEXI bit controls enable/disable of imprecise error exceptions.
Figure 20.3 shows the format of the Debug register and Table 20.16 describes the Debug register fields.
Figure 20.3 Debug Register Format
31
DBD
30
DM
29
No
DCR
28
27
26
Halt
25
24
IBus
EP
23
M
22
21
20
IEXI
19
18
17
EJTAGver
[2:1]
16
LSNM Doze
Count
DM
Check
P
7
Cache
EP
DBus
EP
DDBS
Impr
DDBL
Impr
15
14
10
9
8
6
5
4
3
2
1
0
EJTAG
ver [0]
DExcCode
NoSSt
SSt
0
DINT
DIB
DDBS DDBL
DBp
DSS
Fields
Name Bits
Description
Read/
Write
Reset
State
DBD
31
Indicates whether the last debug exception or exception in
Debug Mode occurred in a branch or jump delay slot:
0: Not in delay slot
1: In delay slot
R
Undefined
DM
30
Indicates that the processor is operating in Debug Mode:
0: Processor is operating in Non-Debug Mode
1: Processor is operating in Debug Mode
R
0
NoDCR
29
Indicates whether the dseg memory segment is present:
0: dseg is present
1: No dseg present
R
Preset
LSNM
28
Controls access of loads/stores between dseg and remaining
memory when dseg is present:
0: Loads/stores in dseg address range go to dseg
1: Loads/stores in dseg address range go to system memory
See section Debug Mode Address Space.
This bit is read-only (R) and reads as zero if not implemented.
R/W
0
Doze
27
Indicates that the processor was in a low-power mode when a
debug exception occurred:
0: Processor not in low-power mode when debug exception
occurred
1: Processor in low-power mode when debug exception
occurred
The Doze bit indicates Reduced Power (RP) and WAIT, and
other implementation-dependent low-power modes.
R
Undefined
Halt
26
Indicates that the internal processor system bus clock was
stopped when the debug exception occurred:
0: Internal system bus clock running
1: Internal system bus clock stopped
Halt indicates WAIT, and other implementation-dependent
events that stop the system bus clock.
R
Undefined
Table 20.16 Debug Register Field Descriptions (Part 1 of 4)