INSTRUCTION SET
S3C8248/C8245/P8245/C8247/C8249/P8249
6-66
PUSH
—
Push To Stack
PUSH
src
Operation:
SP
←
SP – 1
@SP
←
src
A PUSH instruction decrements the stack pointer value and loads the contents of the source
(src) into the location addressed by the decremented stack pointer. The operation then adds the
new value to the top of the stack.
Flags:
No flags are affected.
Format:
Bytes
Cycles
Opcode
(Hex)
Addr Mode
dst
opc
src
2
8 (internal clock)
70
R
8 (external clock)
8 (internal clock)
8 (external clock)
71
IR
Examples:
Given: Register 40H = 4FH, register 4FH = 0AAH, SPH = 00H, and SPL = 00H:
PUSH
40H
→
Register 40H = 4FH, stack register 0FFH = 4FH,
SPH = 0FFH, SPL = 0FFH
PUSH
@40H
→
Register 40H = 4FH, register 4FH = 0AAH, stack register
0FFH = 0AAH, SPH = 0FFH, SPL = 0FFH
In the first example, if the stack pointer contains the value 0000H, and general register 40H the
value 4FH, the statement "PUSH 40H" decrements the stack pointer from 0000 to 0FFFFH. It
then loads the contents of register 40H into location 0FFFFH and adds this new value to the top
of the stack.
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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