S3C8248/C8245/P8245/C8247/C8249/P8249
INSTRUCTION SET
6-79
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.
7
0
C
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".
D:
Unaffected.
H:
Unaffected.
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 S3C8248
Page 31: ...ADDRESS SPACES S3C8248 C8245 P8245 C8247 C8249 P8249 2 20 NOTES ...
Page 107: ...INTERRUPT STRUCTURE S3C8248 C8245 P8245 C8247 C8249 P8249 5 18 NOTES ...
Page 195: ...INSTRUCTION SET S3C8248 C8245 P8245 C8247 C8249 P8249 6 88 NOTES ...
Page 221: ...I O PORTS S3C8248 C8245 P8245 C8247 C8249 P8249 9 16 NOTES ...
Page 245: ...16 BIT TIMER 0 1 S3C8248 C8245 P8245 C8247 C8249 P8249 12 10 NOTES ...
Page 249: ...WATCH TIMER S3C8248 C8245 P8245 C8247 C8249 P8249 13 4 NOTES ...
Page 267: ...A D CONVERTER S3C8248 C8245 P8245 C8247 C8249 P8249 15 6 NOTES ...
Page 299: ...S3P8245 P8249 OTP S3C8248 C8245 P8245 C8247 C8249 P8249 21 8 NOTES ...
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