Hi Rich,

there is no way to do so.
But I suggest the following solution:

Use the data and clock together on all MAX7219
and a separate chip select for every MAX7219.
Or cascade it like given in the data sheet.


Its not impossible to set / clear all 32 port pins indirect,
but very awkward:

toggle_pin:
mov a, pin_number
add a, pin_number
add a, pin_number
mov dptr, pin_table
jmp @a+dptr

pin_table:
cpl p0.0
ret
cpl p0.1
ret
...
cpl p3.7
ret


Another solution, if only for 8 pins of 1 port, e.g. at port P1:

mov pin_mask, #1 ;or 2, 4, ... 80h

then on every changing of the pin:

xch a, pin_mask
xrl p1, a
xch a, pin_mask



Peter