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[/] [light8080/] [trunk/] [c/] [hello.asm] - Rev 76
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; <><><> Small-C V1.2 DOS--CP/M Cross Compiler <><><>
; <><><><><> CP/M Large String Space Version <><><><><>
; <><><><><><><><><><> By Ron Cain <><><><><><><><><><>
;
code
org #0000
ld hl,3072
ld sp,hl
call __main
;//---------------------------------------------------------------------------------------
;// Project: light8080 SOC WiCores Solutions
;//
;// File name: hello.c (February 04, 2012)
;//
;// Writer: Moti Litochevski
;//
;// Description:
;// This file contains a simple program written in Small-C that sends a string to
;// the UART and then switches to echo received bytes.
;// This example also include a simple interrupt example which will work with the
;// verilog testbench. the testbench
;//
;// Revision History:
;//
;// Rev <revnumber> <Date> <owner>
;// <comment>
;//---------------------------------------------------------------------------------------
;// define interrupt vectors
;// note that this file must be edited to enable interrupt used
;#include intr_vec.h
;//---------------------------------------------------------------------------------------
;// Project: light8080 SOC WiCores Solutions
;//
;// File name: intr_vec.h (March 03, 2012)
;//
;// Writer: Moti Litochevski
;//
;// Description:
;// This file contains a simple example of calling interrupt service routine. this
;// file defines the interrupt vector for external interrupt 0 located at address
;// 0x0008. the interrupts vectors addresses are set in the verilog interrupt
;// controller "intr_ctrl.v" file.
;// Code is generated for all 4 supported external interrupts but non used interrupt
;// are not called.
;// On execution of an interrupt the CPU will automatically clear the interrupt
;// enable flag set by the EI instruction. the interrupt vectors in this example
;// enable the interrupts again after interrupt service routine execution. to enable
;// nested interrupts just move the EI instruction to the code executed before the
;// call instruction to the service routine (see comments below).
;// Note that this code is not optimized in any way. this is just an example to
;// verify the interrupt mechanism of the light8080 CPU and show a simple example.
;//
;// Revision History:
;//
;// Rev <revnumber> <Date> <owner>
;// <comment>
;//---------------------------------------------------------------------------------------
;// to support interrupt enable the respective interrupt vector is defined here at the
;// beginning of the output assembly file. only the interrupt vector for used interrupts
;// should call a valid interrupt service routine name defined in the C source file. the
;// C function name should be prefixed by "__".
;#asm
;Preserve space for interrupt routines
;interrupt 0 vector
org #0008
push af
push bc
push de
push hl
; ei ; to enable nested interrupts uncomment this instruction
call __int0_isr
pop hl
pop de
pop bc
pop af
ei ; interrupt are not enabled during the execution os the isr
ret
;interrupt 1 vector
org #0018
push af
push bc
push de
push hl
; call __int1_isr ; interrupt not used
pop hl
pop de
pop bc
pop af
ei
ret
;interrupt 2 vector
org #0028
push af
push bc
push de
push hl
; call __int2_isr ; interrupt not used
pop hl
pop de
pop bc
pop af
ei
ret
;interrupt 3 vector
org #0038
push af
push bc
push de
push hl
; call __int3_isr ; interrupt not used
pop hl
pop de
pop bc
pop af
ei
ret
;//---------------------------------------------------------------------------------------
;// Th.. Th.. Th.. Thats all folks !!!
;//---------------------------------------------------------------------------------------
;// insert c80 assmbly library to the output file
;#include ..\tools\c80\c80.lib
;#asm
;
;------------------------------------------------------------------
; Small-C Run-time Librray
;
; V4d As of July 16, 1980 (gtf)
; Added EXIT() function
;------------------------------------------------------------------
;
;Fetch a single byte from the address in HL and sign extend into HL
ccgchar:
ld a,(hl)
ccsxt:
ld l,a
rlca
sbc a
ld h,a
ret
;Fetch a full 16-bit integer from the address in HL
ccgint:
ld a,(hl)
inc hl
ld h,(hl)
ld l,a
ret
;Store a single byte from HL at the address in DE
ccpchar:
ld a,l
ld (de),a
ret
;Store a 16-bit integer in HL at the address in DE
ccpint:
ld a,l
ld (de),a
inc de
ld a,h
ld (de),a
ret
;Inclusive "or" HL and DE into HL
ccor:
ld a,l
or e
ld l,a
ld a,h
or d
ld h,a
ret
;Exclusive "or" HL and DE into HL
ccxor:
ld a,l
xor e
ld l,a
ld a,h
xor d
ld h,a
ret
;"And" HL and DE into HL
ccand:
ld a,l
and e
ld l,a
ld a,h
and d
ld h,a
ret
;Test if HL = DE and set HL = 1 if true else 0
cceq:
call cccmp
ret z
dec hl
ret
;Test if DE ~= HL
ccne:
call cccmp
ret nz
dec hl
ret
;Test if DE > HL (signed)
ccgt:
ex de,hl
call cccmp
ret c
dec hl
ret
;Test if DE <= HL (signed)
ccle:
call cccmp
ret z
ret c
dec hl
ret
;Test if DE >= HL (signed)
ccge:
call cccmp
ret nc
dec hl
ret
;Test if DE < HL (signed)
cclt:
call cccmp
ret c
dec hl
ret
; Signed compare of DE and HL
; Performs DE - HL and sets the conditions:
; Carry reflects sign of difference (set means DE < HL)
; Zero/non-zero set according to equality.
cccmp:
ld a,e
sub l
ld e,a
ld a,d
sbc h
ld hl,1
jp m,cccmp1
or e ;"OR" resets carry
ret
cccmp1:
or e
scf ;set carry to signal minus
ret
;Test if DE >= HL (unsigned)
ccuge:
call ccucmp
ret nc
dec hl
ret
;Test if DE < HL (unsigned)
ccult:
call ccucmp
ret c
dec hl
ret
;Test if DE > HL (unsigned)
ccugt:
ex de,hl
call ccucmp
ret c
dec hl
ret
;Test if DE <= HL (unsigned)
ccule:
call ccucmp
ret z
ret c
dec hl
ret
;Routine to perform unsigned compare
;carry set if DE < HL
;zero/nonzero set accordingly
ccucmp:
ld a,d
cp h
jp nz,$+5
ld a,e
cp l
ld hl,1
ret
;Shift DE arithmetically right by HL and return in HL
ccasr:
ex de,hl
ld a,h
rla
ld a,h
rra
ld h,a
ld a,l
rra
ld l,a
dec e
jp nz,ccasr+1
ret
;Shift DE arithmetically left by HL and return in HL
ccasl:
ex de,hl
add hl,hl
dec e
jp nz,ccasl+1
ret
;Subtract HL from DE and return in HL
ccsub:
ld a,e
sub l
ld l,a
ld a,d
sbc h
ld h,a
ret
;Form the two's complement of HL
ccneg:
call cccom
inc hl
ret
;Form the one's complement of HL
cccom:
ld a,h
cpl
ld h,a
ld a,l
cpl
ld l,a
ret
;Multiply DE by HL and return in HL
ccmult:
ld b,h
ld c,l
ld hl,0
ccmult1:
ld a,c
rrca
jp nc,$+4
add hl,de
xor a
ld a,b
rra
ld b,a
ld a,c
rra
ld c,a
or b
ret z
xor a
ld a,e
rla
ld e,a
ld a,d
rla
ld d,a
or e
ret z
jp ccmult1
;Divide DE by HL and return quotient in HL, remainder in DE
ccdiv:
ld b,h
ld c,l
ld a,d
xor b
push af
ld a,d
or a
call m,ccdeneg
ld a,b
or a
call m,ccbcneg
ld a,16
push af
ex de,hl
ld de,0
ccdiv1:
add hl,hl
call ccrdel
jp z,ccdiv2
call cccmpbcde
jp m,ccdiv2
ld a,l
or 1
ld l,a
ld a,e
sub c
ld e,a
ld a,d
sbc b
ld d,a
ccdiv2:
pop af
dec a
jp z,ccdiv3
push af
jp ccdiv1
ccdiv3:
pop af
ret p
call ccdeneg
ex de,hl
call ccdeneg
ex de,hl
ret
ccdeneg:
ld a,d
cpl
ld d,a
ld a,e
cpl
ld e,a
inc de
ret
ccbcneg:
ld a,b
cpl
ld b,a
ld a,c
cpl
ld c,a
inc bc
ret
ccrdel:
ld a,e
rla
ld e,a
ld a,d
rla
ld d,a
or e
ret
cccmpbcde:
ld a,e
sub c
ld a,d
sbc b
ret
;// UART IO registers
;port (128) UDATA; // uart data register used for both transmit and receive
;port (129) UBAUDL; // low byte of baud rate register
;port (130) UBAUDH; // low byte of baud rate register
;port (131) USTAT; // uart status register
;// digital IO ports registers
;port (132) P1DATA; // port 1 data register
;port (133) P1DIR; // port 1 direction register control
;port (134) P2DATA; // port 2 data register
;port (135) P2DIR; // port 2 direction register control
;// interrupt controller register
;port (136) INTRENA; // interrupts enable register
;// simulation end register
;// writing any value to this port will end the verilog simulation when using tb_l80soc
;// test bench.
;port (255) SIMEND;
;// registers bit fields definition
;// uart status register decoding
;#define UTXBUSY 1
;#define URXFULL 16
;// globals
;char rxbyte; // byte received from the uart
;int tstary[2] = {1234, 5678};
;//---------------------------------------------------------------------------------------
;// send a single byte to the UART
;sendbyte(by)
__sendbyte:
;char by;
;{
; while (USTAT & UTXBUSY);
cc2:
in a,(131)
call ccsxt
push hl
ld hl,1
pop de
call ccand
ld a,h
or l
jp z,cc3
jp cc2
cc3:
; UDATA = by;
ld hl,2
add hl,sp
call ccgchar
ld a,l
out (128),a
;}
ret
;// check if a byte was received by the uart
;getbyte()
__getbyte:
;{
; if (USTAT & URXFULL) {
in a,(131)
call ccsxt
push hl
ld hl,16
pop de
call ccand
ld a,h
or l
jp z,cc4
; rxbyte = UDATA;
in a,(128)
call ccsxt
ld a,l
ld (__rxbyte),a
; return 1;
ld hl,1
ret
; }
; else
jp cc5
cc4:
; return 0;
ld hl,0
ret
cc5:
;}
ret
;// send new line to the UART
;nl()
__nl:
;{
; sendbyte(13);
ld hl,13
push hl
call __sendbyte
pop bc
; sendbyte(10);
ld hl,10
push hl
call __sendbyte
pop bc
;}
ret
;// sends a string to the UART
;printstr(sptr)
__printstr:
;char *sptr;
;{
; while (*sptr != 0)
cc6:
ld hl,2
add hl,sp
call ccgint
call ccgchar
push hl
ld hl,0
pop de
call ccne
ld a,h
or l
jp z,cc7
; sendbyte(*sptr++);
ld hl,2
add hl,sp
push hl
call ccgint
inc hl
pop de
call ccpint
dec hl
call ccgchar
push hl
call __sendbyte
pop bc
jp cc6
cc7:
;}
ret
;// sends a decimal value to the UART
;printdec(dval)
__printdec:
;int dval;
;{
; if (dval<0) {
ld hl,2
add hl,sp
call ccgint
push hl
ld hl,0
pop de
call cclt
ld a,h
or l
jp z,cc8
; sendbyte('-');
ld hl,45
push hl
call __sendbyte
pop bc
; dval = -dval;
ld hl,2
add hl,sp
push hl
ld hl,4
add hl,sp
call ccgint
call ccneg
pop de
call ccpint
; }
; outint(dval);
cc8:
ld hl,2
add hl,sp
call ccgint
push hl
call __outint
pop bc
;}
ret
;// function copied from c80dos.c
;outint(n)
__outint:
;int n;
;{
;int q;
push bc
; q = n/10;
ld hl,0
add hl,sp
push hl
ld hl,6
add hl,sp
call ccgint
push hl
ld hl,10
pop de
call ccdiv
pop de
call ccpint
; if (q) outint(q);
ld hl,0
add hl,sp
call ccgint
ld a,h
or l
jp z,cc9
ld hl,0
add hl,sp
call ccgint
push hl
call __outint
pop bc
; sendbyte('0'+(n-q*10));
cc9:
ld hl,48
push hl
ld hl,6
add hl,sp
call ccgint
push hl
ld hl,4
add hl,sp
call ccgint
push hl
ld hl,10
pop de
call ccmult
pop de
call ccsub
pop de
add hl,de
push hl
call __sendbyte
pop bc
;}
pop bc
ret
;// sends a hexadecimal value to the UART
;printhex(hval)
__printhex:
;int hval;
;{
;int q;
push bc
; q = hval/16;
ld hl,0
add hl,sp
push hl
ld hl,6
add hl,sp
call ccgint
push hl
ld hl,16
pop de
call ccdiv
pop de
call ccpint
; if (q) printhex(q);
ld hl,0
add hl,sp
call ccgint
ld a,h
or l
jp z,cc10
ld hl,0
add hl,sp
call ccgint
push hl
call __printhex
pop bc
; q = hval-q*16;
cc10:
ld hl,0
add hl,sp
push hl
ld hl,6
add hl,sp
call ccgint
push hl
ld hl,4
add hl,sp
call ccgint
push hl
ld hl,16
pop de
call ccmult
pop de
call ccsub
pop de
call ccpint
; if (q > 9)
ld hl,0
add hl,sp
call ccgint
push hl
ld hl,9
pop de
call ccgt
ld a,h
or l
jp z,cc11
; sendbyte('A'+q-10);
ld hl,65
push hl
ld hl,2
add hl,sp
call ccgint
pop de
add hl,de
push hl
ld hl,10
pop de
call ccsub
push hl
call __sendbyte
pop bc
; else
jp cc12
cc11:
; sendbyte('0'+q);
ld hl,48
push hl
ld hl,2
add hl,sp
call ccgint
pop de
add hl,de
push hl
call __sendbyte
pop bc
cc12:
;}
pop bc
ret
;// external interrupt 0 service routine
;int0_isr()
__int0_isr:
;{
; printstr("Interrupt 0 was asserted."); nl();
ld hl,cc1+0
push hl
call __printstr
pop bc
call __nl
;}
ret
;// program main routine
;main()
__main:
;{
; // configure UART baud rate - set to 9600 for 30MHz clock
; // BAUD = round(<clock>/<baud rate>/16) = round(30e6/9600/16) = 195
; // Note: Usage of a minimum divider value of 1 will accelerate the RTL simulation.
; UBAUDL = 195;
ld hl,195
ld a,l
out (129),a
; UBAUDH = 0;
ld hl,0
ld a,l
out (130),a
; // configure both ports to output and digital outputs as zeros
; P1DATA = 0x00;
ld hl,0
ld a,l
out (132),a
; P1DIR = 0xff;
ld hl,255
ld a,l
out (133),a
; P2DATA = 0x00;
ld hl,0
ld a,l
out (134),a
; P2DIR = 0xff;
ld hl,255
ld a,l
out (135),a
; // enable interrupt 0 only
; INTRENA = 0x01;
ld hl,1
ld a,l
out (136),a
; // enable CPU interrupt
;#asm
ei
; // print message
; printstr("Hello World!!!"); nl();
ld hl,cc1+26
push hl
call __printstr
pop bc
call __nl
; printstr("Dec value: "); printdec(tstary[1]); nl();
ld hl,cc1+41
push hl
call __printstr
pop bc
ld hl,__tstary
push hl
ld hl,1
add hl,hl
pop de
add hl,de
call ccgint
push hl
call __printdec
pop bc
call __nl
; printstr("Hex value: 0x"); printhex(tstary[0]); nl();
ld hl,cc1+53
push hl
call __printstr
pop bc
ld hl,__tstary
push hl
ld hl,0
add hl,hl
pop de
add hl,de
call ccgint
push hl
call __printhex
pop bc
call __nl
; // assert bit 0 of port 1 to test external interrupt 0
; P1DATA = 0x01;
ld hl,1
ld a,l
out (132),a
;
; printstr("Echoing received bytes: "); nl();
ld hl,cc1+67
push hl
call __printstr
pop bc
call __nl
; // loop forever
; while (1) {
cc13:
ld hl,1
ld a,h
or l
jp z,cc14
; // check if a new byte was received
; if (getbyte())
call __getbyte
ld a,h
or l
jp z,cc15
; // echo the received byte to the UART
; sendbyte(rxbyte);
ld a,(__rxbyte)
call ccsxt
push hl
call __sendbyte
pop bc
; }
cc15:
jp cc13
cc14:
;}
ret
;//---------------------------------------------------------------------------------------
;// Th.. Th.. Th.. Thats all folks !!!
;//---------------------------------------------------------------------------------------
cc1:
db 73,110,116,101,114,114,117,112,116,32
db 48,32,119,97,115,32,97,115,115,101
db 114,116,101,100,46,0,72,101,108,108
db 111,32,87,111,114,108,100,33,33,33
db 0,68,101,99,32,118,97,108,117,101
db 58,32,0,72,101,120,32,118,97,108
db 117,101,58,32,48,120,0,69,99,104
db 111,105,110,103,32,114,101,99,101,105
db 118,101,100,32,98,121,116,101,115,58
db 32,0
__rxbyte:
ds 1
__tstary:
db -46,4,46,22
; --- End of Compilation ---
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