ADDRESSING MODES
S3C8248/C8245/P8245/C8247/C8249/P8249
3-12
INDIRECT ADDRESS MODE (IA)
In Indirect Address (IA) mode, the instruction specifies an address located in the lowest 256 bytes of the program
memory. The selected pair of memory locations contains the actual address of the next instruction to be
executed. Only the CALL instruction can use the Indirect Address mode.
Because the Indirect Address mode assumes that the operand is located in the lowest 256 bytes of program
memory, only an 8-bit address is supplied in the instruction; the upper bytes of the destination address are
assumed to be all zeros.
Current
Instruction
Program Memory
Locations 0-255
Program Memory
OPCODE
dst
Lower Address Byte
Upper Address Byte
Next Instruction
LSB Must be Zero
Sample Instruction:
CALL
#40H
; The 16-bit value in program memory addresses 40H
and 41H is the subroutine start address.
Figure 3-12. Indirect Addressing
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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