Bob Ammerman [rammerman at prodigy.net] of RAm Systems says
The PIC18Cxx2 chips contain quite a few nice new features. One of the neatest is programmable access to the stack. This feature allows many powerful tricks.
- this code has _NOT_ been tested!
- all multi-byte values are little-endian
- I assume the code space never exceeds 16 bits worth (which it never will on the 242, 252, 442 or 452 chips).Co-routines/tasks version 2 Allows cocalls from subroutines. Works by allocating parts of the stack space to each coroutine/task. Note: limits the available stack depth for each task. There is no checking if one task overruns anothers stack! CBLOCK TASKX_SP ; STKPTR for task X TASKY_SP ; STKPTR for task Y ENDC initialize: ; initialize values for all but the first task movlw 16 ; start tasky's stack at level 16 movwf TASKY_SP,A movwf STKPTR,A movlw low(tasky) movwf TOSL,A movlw high(tasky) movwf TOSH,A clrf STKPTR,A ; back to first task's stack area ...fall thru into first task... taskx: . . . rcall x_cocall_y . . rcall x_cocall_y . bra taskx x_cocall_y: movff STKPTR,TASKX_SP movff TASKY_SP,STKPTR return tasky: . . . rcall y_cocall_x . . rcall y_cocall_x . bra tasky y_cocall_x: movff STKPTR,TASKY_SP movff TASKX_SP,STKPTR return
|file: /Techref/microchip/18c/multitask-coop2-ba.htm, 1KB, , updated: 2000/10/12 11:14, local time: 2018/1/21 08:30,
|©2018 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions?|
<A HREF="http://techref.massmind.org/techref/microchip/18c/multitask-coop2-ba.htm"> PIC 18C Microcontoller Program Flow Method for Co-routines/tasks Allows all cocalls</A>
|Did you find what you needed?|
Welcome to massmind.org!
Welcome to techref.massmind.org!