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S3C9454B/F9454B
SAM88RCRI INSTRUCTION SET
6-45
SRA
— Shift Right Arithmetic
SRA
dst
Operation:
dst (7)
←
dst (7)
C
←
dst (0)
dst (n)
←
dst (n + 1), n = 0–6
An arithmetic shift-right of one bit position is performed on the destination operand. Bit zero (the
LSB) replaces the carry flag. The value of bit 7 (the sign bit) is unchanged and is shifted into bit
position 6.
C
7
0
6
Flags:
C:
Set if the bit shifted from the LSB position (bit zero) was "1".
Z:
Set if the result is "0"; cleared otherwise.
S:
Set if the result is negative; cleared otherwise.
V:
Always cleared to "0".
Format:
Bytes
Cycles
Opcode
(Hex)
Addr Mode
dst
opc
dst
2
4
D0
R
4
D1
IR
Examples:
Given: Register 00H = 9AH, register 02H = 03H, register 03H = 0BCH, and C = "1":
SRA
00H
→
Register 00H = 0CD, C = "0"
SRA
@02H
→
Register 02H = 03H, register 03H = 0DEH, C = "0"
In the first example, if general register 00H contains the value 9AH (10011010B), the statement
"SRA 00H" shifts the bit values in register 00H right one bit position. Bit zero ("0") clears the C flag
and bit 7 ("1") is then shifted into the bit 6 position (bit 7 remains unchanged). This leaves the
value 0CDH (11001101B) in destination register 00H.
Summary of Contents for S3C9454B
Page 1: ...S3C9454B F9454B 8 BIT CMOS MICROCONTROLLER USER S MANUAL Revision 1 ...
Page 25: ...PRODUCT OVERVIEW S3C9454B F9454B 1 10 NOTES ...
Page 35: ...ADDRESS SPACES S3C9454B F9454B 2 10 NOTES ...
Page 65: ...CONTROL REGISTERS S3C9454B F9454B 4 18 NOTES ...
Page 123: ...CLOCK CIRCUIT S3C9454B F9454B 7 4 NOTES ...
Page 133: ...RESET and POWER DOWN S39454B F9454B 8 10 NOTES ...
Page 145: ...I O PORTS S3C9454B F9454B 9 12 NOTES ...
Page 173: ...A D CONVERTER S3C9454B F9454B 12 8 NOTES ...
Page 183: ...ELECTRICAL DATA S3C9454B F9454B 13 10 NOTES ...