#****************************************************************************************
#  PIC32MX120F032B Sample Program
#   Project      :
#   Program Name :
#   Programer    :
#   Create date  :  Version 1.0    H24.06.14
#   History      :
#   Laungage     :  Gcc (MPLAB C32) Asm 
#*****************************************************************************************
#   Description
#    (1)Memory load map
#        Config words : Physical(0x1FC00BF0-0x1FC00BFF)/Virtual(0xBFC00BF0-0xBFC00BFF)
#        RAM          : Physical(0x00000000-0x00001FFF)/Virtual(0x80000000-0x80001FFF)
#        Program memory:Physical(0x1D000000-0x1D007FFF)/Virtual(0x9D000000-0x9D007FFF)
#        SFRs         : Physical(0x1F800000-0x1F8FFFFF)/Virtual(0xBF800000-0xBF8FFFFF)
#    (2)Assembler File extension
#        ****.S  (S:Preprocessed Source file / s:Source file)
#    (3)Compile   Gcc(C32)
#    (4)general purpose register ( 32bit * 32 )  Śmemo
#         $0(Fixed 0), $1(not use), $2-$3(v0-v1:return-value register), $4-$7(a0-a3:argument register)
#         $8-$15,$24-$25(t0-t9:free), $16-$23,$30(s0-s8:free), $26-$27(k0-k1:OS/not use), $28(gp:groval pointer)
#         $29(sp:stack pointer), $31(ra:return adress)
#         $f0,                   $12/13,$14/15(float type pare)
#*****************************************************************************************
#include <p32xxxx.h>

#
#  Define config words
#
.section .config_1FC00BF0,code // USERID,PMDL1WAY,IOL1WAY,FUSBIDIO,FVBUSONIO 
        .word 0x3FFFFFFF
.section .config_1FC00BF4,code // FPLLIDIV,FPLLMUL         
        .word 0xFFF8FF88       // Internal OSC 8MHz    
.section .config_1FC00BF8,code // FNOSC,FSOSCEN,IESO,POSCMOD,OSCIOFNC,FPBDIV,FCKSM,WDTPS,FWDTEN,FWDTWINSZ 
        .word 0xFD60CF58       // Internal OSC 8MHz       
.section .config_1FC00BFC,code // JTAGEN,ICESEL,PWP,BWP,CP 
        .word 0x7FFFFFE3

#
#  Program main
#
        .global main
        .global wat
        .text            // Start text area 
        .set noreorder   // Don't optimize the order of the instructions as well as don't insert 'nop' instructions after jumps and branches. 
        .ent main
main:
# *******************
#  1.Initialize
# *******************
# (1)Define PortB
        li      t0, 0x0000FF00       // 0x0000FF00  => t0-Register 
        sw      t0, TRISB($0)        // t0-Register => TRISB+0     
        li      t0, 0x00000001       // 0x00000001  => t0-Register 
        sw      t0, 0x80000000($0)   // t0-Register => Ram 0x80000000   
        sw      t0, PORTB($0)        // t0-Register => PORTB+0     

# *******************
#  2.Program main
# *******************
main1:
        jal     mvLED                // CALL mvLED 
        nop

        jal     wat                  // wait 
        nop

        j       main1
        nop
       .end main

#******************************************************************************************
#   Function Name : mvLED
#   Title         : Move LED function
#   Input         :
#   Output        :
#******************************************************************************************
       .ent mvLED
mvLED:
# *******************
#  1.Initialize
# *******************
        addiu   sp, sp, -4
        sw      t0, 0(sp)
        addiu   sp, sp, -4
        sw      t1, 0(sp)
        addiu   sp, sp, -4
        sw      t2, 0(sp)
        addiu   sp, sp, -4
        sw      t3, 0(sp)
        addiu   sp, sp, -4
        sw      t4, 0(sp)
        addiu   sp, sp, -4
        sw      t5, 0(sp)
        addiu   sp, sp, -4
        sw      t6, 0(sp)

        li      t4, 0x00000100       /* 0x000FFFFF  => t2-Register */
        li      t1, 0x00000002       /* 0x00000001  => t1-Register */
        li      t0, 0x00000001       /* 0x00000000  => t0-Register */
        lw      t6, 0x80000000($0)   /* Ram 0x80000000 => t6-Register */
  
# *******************
#  2.Function main
# *******************
        move    t2, t6               /* t2 <= s0       */
        mult    t2, t1               /* t2 * t1        */
        nop
        nop
        mflo    t3                   /* t3 <= LO       */
        slt     t5, t3, t4           /* t3 ƒ t4 => t5 */
        bne     t5, $0 , mvLED1      /* t5 != 0        */   
        nop

        sw      t0, 0x80000000($0)   /* t0-Register => Ram 0x80000000 */ 
        sw      t0, PORTB($0)        /* t0-Register => PORTB+0 */   

        j       mvLEDE               /* GOTO mvLEDE    */
        nop
mvLED1:
        sw      t3, 0x80000000($0)   /* t3-Register => Ram 0x80000000 */ 
        sw      t3, PORTB($0)        /* t3-Register => PORTB+0 */   

# *******************
#  3.Function end
# *******************
mvLEDE:
        lw      t6, 0(sp)
        addiu   sp, sp, 4
        lw      t5, 0(sp)
        addiu   sp, sp, 4
        lw      t4, 0(sp)
        addiu   sp, sp, 4
        lw      t3, 0(sp)
        addiu   sp, sp, 4
        lw      t2, 0(sp)
        addiu   sp, sp, 4
        lw      t1, 0(sp)
        addiu   sp, sp, 4
        lw      t0, 0(sp)
        addiu   sp, sp, 4

        jr      ra          /* Return */
        nop
       .end mvLED

#******************************************************************************************
#   Function Name : wat
#   Title         : wait loop
#   Input         :
#   Output        :
#******************************************************************************************
       .ent wat
wat:
# *******************
#  1.Initialize
# *******************
        addiu   sp, sp, -4
        sw      t0, 0(sp)
        addiu   sp, sp, -4
        sw      t1, 0(sp)
        addiu   sp, sp, -4
        sw      t2, 0(sp)

# *******************
#  2.Function main
# *******************
        li      t2, 0x000FFFFF       /* 0x000FFFFF  => t2-Register */
        li      t1, 0x00000001       /* 0x00000001  => t1-Register */
        li      t0, 0x00000000       /* 0x00000000  => t0-Register */
wat1:
        sub     t3, t2, t1           /* t3 <= t2 - t1 */  
        move    t2, t3               /* t2 <= t3      */ 
        bne     t2, t0 , wat1        /* t2 != t0      */   
        nop
wat2:
# *******************
#  3.Function end
# *******************
        lw      t2, 0(sp)
        addiu   sp, sp, 4
        lw      t1, 0(sp)
        addiu   sp, sp, 4
        lw      t0, 0(sp)
        addiu   sp, sp, 4

        jr      ra                   /* Return        */
        nop
       .end wat