Status register st0, Status register st1 – Texas Instruments TMS320C2XX User Manual
Page 440
Register Descriptions
A-5
Register Summary
Status Register ST0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
X
X
X
0
X
ЙЙЙ
ЙЙЙ
1
†
1
X
X
X
X
X
X
X
X
X
ARP
OV
OVM
INTM
DP
All unmasked interrupts enabled
All unmasked interrupts disabled
0
1
Auxiliary register pointer
Selects the current page
(0, 1, 2, ..., 511) in
data memory
Data page pointer
R/W
R/W
R/W
Selects the current auxiliary register
(0, 1, 2, 3, 4, 5, 6, or 7)
R/W
Accumulator results overflow normally.
Overflow mode selected
0
1
Flag is reset
Overflow detected in accumulator
0
1
R/W
Interrupt mode
Overflow mode
Overflow flag
† This reserved bit is always read as 1. Writes have no effect.
Status Register ST1
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
X
X
X
0
X
1
1
ЙЙ
ЙЙ
1
†
ЙЙ
ЙЙ
1
†
ЙЙЙ
ЙЙЙ
1
†
ЙЙ
ЙЙ
1
†
1
ЙЙЙ
ЙЙЙ
1
†
ЙЙ
ЙЙ
1
†
0
0
ARB
CNF
TC
SXM
C
XF
PM
Auxiliary register pointer buffer
Product shift mode
R/W
R/W
R/W
Holds previous ARP value
R/W
Holds results of various software tests
DARAM B0 mapped to data memory
DARAM B0 mapped to program memory
0
1
R/W
R/W
Test/control flag
Sign extension suppressed
Sign extension mode selected
0
1
R/W
Carry not generated/borrow generated
Carry generated/borrow not generated
0
1
XF pin low
XF pin high
0
1
No shift
Left shift of 1
Left shift of 4
Right shift of 6, sign extended
0
1
0
1
0
0
1
1
Carry bit
XF pin status
Sign-extension mode
DARAM B0 configuration
† These reserved bits are always read as 1s. Writes have no effect.