
IDT MIPS32 4Kc Processor Core
CP0 Registers
79RC32438 User Reference Manual
2 - 68
November 4, 2002
Notes
Processor Identification (CP0 Register 15, Select 0)
The Processor Identification (PRId) register is a 32-bit read-only register that contains information iden-
tifying the manufacturer, manufacturer options, processor identification, and revision level of the processor.
PRId Register Format
31
Config Register (CP0 Register 16, Select 0)
The Config register specifies various configuration and capabilities information. Most of the fields in the
Config register are initialized by hardware during the Reset exception process, or are constant. One field,
K0, must be initialized by software in the Reset exception handler.
Register Format — Select 0
31 30
28 27
Fields
Description
Read/
Write
Reset
State
Name
Bit(s)
EPC
31:0
Exception Program Counter
R/W
Undefined
Table 2.42 EPC Register Field Description
24 23
16 15
8 7
0
R
Company ID
Processor ID
Revision
Fields
Description
Read/
Write
Reset
State
Name
Bit(s)
R
31:24
Reserved. Must be ignored on write and read as
zero.
R
0
Company
ID
23:16
Identifies the company that designed or manufac-
tured the processor. In all three cores this field con-
tains a value of 1 to indicate MIPS Technologies, Inc.
R
1
Processor
ID
15:8
Identifies the type of processor. This field allows soft-
ware to distinguish between the various types of
MIPS Technologies processors. This field contains a
value of 0x80 for the 4Kc processor.
R
0x80
Revision
7:0
Specifies the revision number of the processor. This
field allows software to distinguish between one revi-
sion and another of the same processor type. Cur-
rent values are:
0x1: 1.1-2.2
0x2: 2.3-2.4
0x3: 2.5-2.6
0x4: 3.0
0x5: 3.1
0x6: 3.2
0x7: 3.3
0x8: 3.4
0x9: 3.5
R
Preset
Table 2.43 PRId Register Field Descriptions
25 24
21
20
19 18 17 16 15 14 13 12
10 9
7 6
3 2
0
M
K23
KU
R
MDU R MM BMBE AT
AR
MT
0
K0