Test Bit Specified by TREG
BITT
7-47
Assembly Language Instructions
Syntax
BITT
dma
Direct addressing
BITT
ind [, ARn]
Indirect addressing
Operands
dma:
7 LSBs of the data-memory address
n:
Value from 0 to 7 designating the next auxiliary register
ind:
Select one of the following seven options:
* *+ *– *0+ *0– *BR0+ *BR0–
BITT
dma
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
1
1
0
1
1
1
1
0
dma
BITT
ind [, ARn]
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0
1
1
0
1
1
1
1
1
ARU
N
NAR
Note:
ARU, N, and NAR are defined in Section 6.3,
Indirect Addressing Mode (page 6-9).
Execution
Increment PC, then ...
(data bit number (15 –TREG(3:0)))
→
TC
Status Bits
Affects
TC
Description
The BITT instruction copies the specified bit of the data-memory value to the
TC bit of status register ST1. Note that the BITT, CMPR, LST #1, and NORM
instructions also affect the TC bit in status register ST1. The bit number is spe-
cified by a bit code value contained in the four LSBs of the TREG, as shown
in Figure 7–2.
Figure 7–2. Bit Numbers and Their Corresponding Bit Codes for BITT Instruction
Bit code (in 4 LSBs of
TREG)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Bit number
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
MSB
Data-memory value
LSB
Words
1
Opcode