[Pyastra-general] Re:Finding out more about Pyastra

[Alex <es...@ya...>]

Hello,

Current architecture of Pyastra is temporary. First standard python 
module "parser" converts given file to a tree. Second stage is made by 
tree2tree.py optimizer (currently it does nothing at all). Then it is 
converted by tree2asm.py to assembler.

More details is planned to be published at project's homepage near the 
release 0.0.1.

As an example i made a classic example (blinking LEDs):

PORTA=fbin('0101 0101')

while (1):
    PORTA ^= 0xff
    for i in xrange(0, 255):
        pass

It is converted to the following PIC16 assebler code:

;
; Generated by pyastra 0.0.1
; infile: tests/hello_world.py
;

	processor	16f877
	#include	p16f877.inc
        
_lshift_left	equ	0x21	;bank -1
_lshift_right	equ	0x22	;bank -1
_rshift_left	equ	0x23	;bank -1
_rshift_right	equ	0x24	;bank -1
_mul_left	equ	0x25	;bank -1
_mul_right	equ	0x26	;bank -1
mul_cntr	equ	0x27	;bank -1
mul_res	equ	0x28	;bank -1
_div_left	equ	0x29	;bank -1
_div_right	equ	0x2a	;bank -1
div_cntr	equ	0x2b	;bank -1
div_buf	equ	0x2c	;bank -1
_mod_left	equ	0x2d	;bank -1
_mod_right	equ	0x2e	;bank -1
mod_cntr	equ	0x2f	;bank -1
mod_buf	equ	0x30	;bank -1
_pow_left	equ	0x31	;bank -1
_pow_right	equ	0x32	;bank -1
pow_res	equ	0x33	;bank -1
pow_buf	equ	0x34	;bank -1
pow_cntr	equ	0x35	;bank -1
stack0	equ	0x36	;bank -1
_i	equ	0x37	;bank -1
stack1	equ	0x38	;bank -1

	org	0x0
	nop
	goto	main

	org	0x4
main
	movlw	0x55
	movwf	stack0
	bcf	STATUS,	RP0
	bcf	STATUS,	RP1
	movwf	PORTA

label0
	movlw	0x1
	movwf	stack0
	btfsc	STATUS,	Z
	goto	label1

	movlw	0xff
	movwf	stack0
	bcf	STATUS,	RP0
	bcf	STATUS,	RP1
	xorwf	PORTA,	f
	clrf	_i
	movlw	0xff
	movwf	stack1
	movwf	stack0

label2
	movf	stack0,	w
	subwf	_i,	w
	btfsc	STATUS,	Z
	goto	label3
	btfsc	STATUS,	C
	goto	label3

label4
	incf	_i,	f
	goto	label2

label3
	goto	label0

label1
	goto	$

	end


And that's the output of Pyastra:

Peak RAM usage: 25 byte(s) (6.8%)
Program memory usage: 30 word(s) (0.4%)
NOTE: statistics includes ICD memory usage!


Best regards,
Alex Ziranov.

Wise Jeff-Q16332 wrote:
 > Hi,
 >
 > I'm interested in finding out more about Pyastra and how it works. 
For example, what
 > python code would translate to what PIC code.
 >
 > Thanks,
 > ...Jeff Wise