Echelon Neuron - Manual (Page 116)

Examples:
The following example assumes that the stack contains two 16-bit elements, A
and B, with A nearest to the top of the stack. The example places a copy of B in
TOS and NEXT.
Example APEXP ; ( a(2), b(2) -– b(2), a(2), b(2) )
push [dsp][-2] ; ( msb(b), a(2), b(2) )
push [dsp][-2] ; ( lsb(b), a(2), b(2) )
ret ; ( b(2), a(2), b(2) )
The following example loads TOS with the contents of the general-purpose
register R0.
R0 EQU 8
Example APEXP ; ( -- r0)
push !R0 ; ( r0 )
ret ; return to caller
The following example calls the do_it_n function N times, with N >= 0 in TOS.
The number of remaining invocations is passed to the do_it_n function with each
call, which consumes its argument.
Example APEXP ; ( n -- )
poppush ; ( ) R(n)
loop_body ; ( ) R(n)
push [rsp] ; ( n ) R(n)
dec ; ( n-- ) R(n)
callf do_it_n ; ( ) R(n)
dbrnz loop_body ; ( ) R({n})
ret ; ( ) R( )
The following example loads TOS with the content of N-th byte in the base page.
N is passed into this example function in TOS.
Example APEXP ; ( n -– v )
push !tos ; ( n, v -- )
drop_r tos ; ( v )
106 Neuron Assembly Language Instruction Statements