CPU Multiport Register File
3-2
3.1
CPU Multiport Register File
The ’C3x provides 28 registers in a multiport register file that is tightly coupled to
the CPU. The program counter (PC) is not included in the 28 registers. All of these
registers can be operated on by the multiplier and the ALU and can be used as
general-purpose 32-bit registers.
Table 3–1 lists the registers’ names and assigned functions of the ’C3x.
Table 3–1. CPU Registers
Register
Symbol
Register
Machine
Value (hex)
Assigned Function Name
Section
Page
R0
00
Extended-precision register 0
3.1.1
3-3
R1
01
Extended-precision register 1
3.1.1
3-3
R2
02
Extended-precision register 2
3.1.1
3-3
R3
03
Extended-precision register 3
3.1.1
3-3
R4
04
Extended-precision register 4
3.1.1
3-3
R5
05
Extended-precision register 5
3.1.1
3-3
R6
06
Extended-precision register 6
3.1.1
3-3
R7
07
Extended-precision register 7
3.1.1
3-3
AR0
08
Auxiliary register 0
3.1.2
3-4
AR1
09
Auxiliary register 1
3.1.2
3-4
AR2
0A
Auxiliary register 2
3.1.2
3-4
AR3
0B
Auxiliary register 3
3.1.2
3-4
AR4
0C
Auxiliary register 4
3.1.2
3-4
AR5
0D
Auxiliary register 5
3.1.2
3-4
AR6
0E
Auxiliary register 6
3.1.2
3-4
AR7
0F
Auxiliary register 7
3.1.2
3-4
DP
10
Data-page pointer
3.1.3
3-4
IR0
11
Index register 0
3.1.4
3-4
IR1
12
Index register 1
3.1.4
3-4
BK
13
Block-size register
3.1.5
3-4
SP
14
System-stack pointer
3.1.6
3-4
ST
15
Status register
3.1.7
3-5
IE
16
CPU/DMA interrupt
-
enable
3.1.8
3-9
IF
17
CPU interrupt flags
3.1.9
3-11
IOF
18
I/O flags
3.1.10
3-16
RS
19
Repeat start-address
3.1.11
3-17
RE
1A
Repeat end-address
3.1.11
3-17
RC
1B
Repeat counter
3.1.11
3-17