Echelon Neuron - Manual (Page 112)

PUSH (Push onto Stack)
The PUSH instructions push a value from a specified location onto the data
stack. The PUSH instruction uses one of the following addressing modes:
• In the indirect relative addressing mode, the PUSH [pointer-
register][offset] instruction pushes the value from the location specified
by adding (using unsigned arithmetic) the contents of the specified
pointer register with the specified offset value into TOS. The value of the
pointer-register expression must be in the range 0 to 3. The offset
expression must resolve at link time to a value in the range 0 to 255.
• In the indirect indexed addressing mode, the PUSH [pointer-register]
[TOS] instruction pushes the value from the location specified by adding
(using unsigned arithmetic) the contents of the specified pointer register
with the value of TOS into NEXT. This instruction modifies NEXT but
preserves TOS. The value of the pointer-register expression must be in
the range 0 to 3.
• In the direct addressing mode, the PUSH register instruction pushes the
value from the specified CPU register into TOS. The register can be DSP,
FLAGS, or RSP. Because a PUSH instruction always increments DSP,
the value in TOS after a PUSH DSP instruction is one greater than the
original DSP value. And because the FLAGS register contains the Carry
flag, the PUSH FLAGS instruction allows you to inspect the Carry flag.
• In the DSP relative addressing mode, the PUSH [DSP][offset]
instruction pushes the value from the stack location (relative to DSP)
specified by offset into TOS. The value of offset must be in the range -1 to
-8. Location -1 corresponds to the first byte on the stack below NEXT.
• In the absolute addressing mode, the PUSH address instruction pushes
the value from the absolute address specified by address into TOS.
• In the direct addressing mode, the PUSH register instruction pushes the
value from the specified register into TOS. The value of register must be
either TOS or NEXT.
• In the immediate addressing mode, the PUSH #number instruction
pushes the value from the specified number into TOS. The expression
number must resolve at link time to a value in the range -128 to +127.
See also PUSHS (Push Short).
• In the BP relative addressing mode, the PUSH !byte-register instruction
pushes the value from the specified general-purpose byte register
(R0..R15) into TOS. The byte-register expression must resolve at link
time to a value in the range 8 to 23 for general-purpose byte registers R0
to R15, respectively.
• In the indirect addressing mode, the PUSH [RSP] instruction pushes the
byte on the top of the return stack into TOS. The byte on top of the
return stack is not consumed by this instruction and the return stack
pointer (RSP) remains unchanged.
• In the BP indexed addressing mode, the PUSH !TOS instruction pushes
the value from a location specified by adding TOS to the contents of the
102 Neuron Assembly Language Instruction Statements