LSI 53C810A User Manual
Page 169
Transfer Control Instructions
6-29
If the comparisons are false, the LSI53C810A fetches the
next instruction from the address pointed to by the
register and the instruction
pointer is not modified.
Return Instruction
The LSI53C810A can do a true/false comparison of the
ALU carry bit, or compare the phase and/or data as
defined by the Phase Compare, Data Compare, and
True/False bit fields.
If the comparisons are true, then it loads the
register with the contents of the
DMA SCRIPTS Pointer Save (DSPS)
register. That
address value becomes the address of the next
instruction.
When a Return instruction is executed, the value stored
in the
register is returned to the
register. The LSI53C810A does
not check to see whether the Call instruction has already
been executed. It does not generate an interrupt if a
Return instruction is executed without previously
executing a Call instruction.