; LED Blink Example program, for use with the PJRC 8051 ; Development Circuit Board, Rev 4. ; ; http://www.pjrc.com/tech/8051/board4/blink_as31.html ;This line configures where the program will go into memory. ;2000 to 7FFF is RAM, which is the best place to download ;while testing your code. Memory from 8000 to F7FF is Flash ;ROM, which is non-volatile. You MUST ERASE the flash rom ;if the area you will use already has data in it. Unlike ;easily re-writable RAM, writing to flash rom can only chang ;1's into 0's. To change the 0's back into 1's, you must ;erase the flash (which turns a section or all of it into ;0xFFs to all you to download again). 0000: .equ locat, 0x2000 ;Location for this program ;82C55 memory locations, Rev 4 0000: .equ port_a, 0xF800 ;access port A 0000: .equ port_b, 0xF801 ;access port B 0000: .equ port_c, 0xF802 ;access port C 0000: .equ port_abc_pgm, 0xF803 ;configure in/out of all th 0000: .equ port_d, 0xF900 ;access port D 0000: .equ port_e, 0xF901 ;access port E 0000: .equ port_f, 0xF902 ;access port F 0000: .equ port_def_pgm, 0xF903 ;configure in/out of all th ; Useful routines in PAULMON2 that you can call. When you ; later want a stand-alone application, you can copy them ; from the PAULMON2 source code (or write you own if you lik 0000: .equ cout, 0x0030 ;print byte in acc to seria 0000: .equ cin, 0x0032 ;get byte from serial port 0000: .equ phex, 0x0034 ;print acc in hex (2 digits 0000: .equ phex16, 0x0036 ;print dptr in hex (4 digit 0000: .equ pstr, 0x0038 ;print a string @dptr 0000: .equ esc, 0x003E ;paulmon2's check for esc k 0000: .equ newline, 0x0048 ;print a newline (CR and LF 0000: .equ pint8u, 0x004D ;print acc as unsigned int 0000: .equ pint16u, 0x0053 ;print dptr as unsigned int ;Program Header. This is what PAULMON2 looks for to display ;program in its memory usage and run menus. You would norma ;run this program with 'R', but you can also jump to 2040 (o 2000: .org locat 2000: A5 E5 E0 A5 .db 0xA5,0xE5,0xE0,0xA5 ;signiture bytes 2004: 23 FF 00 00 .db 35,255,0,0 ;id (35=prog) 2008: 00 00 00 00 .db 0,0,0,0 ;prompt code vector 200C: 00 00 00 00 .db 0,0,0,0 ;reserved 2010: 00 00 00 00 .db 0,0,0,0 ;reserved 2014: 00 00 00 00 .db 0,0,0,0 ;reserved 2018: 00 00 00 00 .db 0,0,0,0 ;user defined 201C: FF FF FF FF .db 255,255,255,255 ;length and checksum (255=un 2020: 42 6C 69 6E 6B 20 4C 45 44 73 00 .db "Blink LEDs",0 ;max 31 characters, plus the 2040: .org locat+64 ;executable code begins here ;Finally, the actual code.... much shorter than all these co ;that try to explain how to set everything up! startup: 2040: 90 F9 03 mov dptr, #port_def_pgm 2043: 74 80 mov a, #128 2045: F0 movx @dptr, a ;make all D-E-F port pins o begin: 2046: 90 20 7A mov dptr, #table ;DPTR will keep track of wh ;the table we will do next loop: 2049: E4 clr a 204A: 93 movc a, @a+dptr ;get pattern to display 204B: 11 5F acall update 204D: A3 inc dptr 204E: 12 00 3E lcall esc ;abort if the user presses 2051: 40 09 jc exit 2053: E4 clr a 2054: 93 movc a, @a+dptr ;get time to display this p 2055: 60 EF jz begin ;restart when we hit the en 2057: 11 6C acall delay 2059: A3 inc dptr 205A: 80 ED sjmp loop ;keep doing the animation.. 205C: 02 00 00 exit: ljmp 0 ;write the bit pattern in Acc to port E. We need t ;save DPTR (holding our position in the table) befo ;using DPTR to access the 82C55 chip. update: 205F: C0 83 push dph 2061: C0 82 push dpl 2063: 90 F9 01 mov dptr, #port_e 2066: F0 movx @dptr, a 2067: D0 82 pop dpl 2069: D0 83 pop dph 206B: 22 ret ;delay for a number of ms (specified by acc) delay: 206C: F8 mov r0, a 206D: 79 E6 dly2: mov r1, #230 206F: 00 dly3: nop 2070: 00 nop 2071: 00 nop ;6 NOPs + DJNZ is 4.34 us 2072: 00 nop ;with the 22.1184 MHz cryst 2073: 00 nop 2074: 00 nop 2075: D9 F8 djnz r1, dly3 ;repeat 230 times for 1 ms 2077: D8 F4 djnz r0, dly2 ;repeat for specified # of 2079: 22 ret ;The data table that is read by the MOVC instructio 207A: 7F 5A table: .db 01111111b, 90 207C: 3F 46 .db 00111111b, 70 207E: 1F 32 .db 00011111b, 50 2080: 8F 28 .db 10001111b, 40 2082: C7 28 .db 11000111b, 40 2084: E3 28 .db 11100011b, 40 2086: F1 28 .db 11110001b, 40 2088: F8 32 .db 11111000b, 50 208A: FC 46 .db 11111100b, 70 208C: FE 5A .db 11111110b, 90 208E: FC 46 .db 11111100b, 70 2090: F8 32 .db 11111000b, 50 2092: F1 28 .db 11110001b, 40 2094: E3 28 .db 11100011b, 40 2096: C7 28 .db 11000111b, 40 2098: 8F 28 .db 10001111b, 40 209A: 1F 32 .db 00011111b, 50 209C: 3F 46 .db 00111111b, 70 209E: FF 00 .db 255,0 ;zero marks end of table