esl_external_read_data.asm

义隆公司eSLZ000 dsp处理芯片一个播放midi的样例程序。

.IFNDEF	@_LIB_EXTERNAL_READ_DATA_ASM
@_LIB_EXTERNAL_READ_DATA_ASM		.EQU		1

.DATA


.CODE

;*****************************************************************************************
; SUBROUTINE: EXTERNAL_READ_WORD
; DESCRIPTION: Read one word data from external memory(Mode: Byte Mode).
; 
; We support 3 types external memory playing Speech(supprt SPI,NOR,NAND)
;
; If user want to use the external memory access method, 
; such as "Melody" application, you should remove the "//" from
; //    CALL @_LIB_F_SPI_RX_2BYTE
; 
; and such as "Speech" application, you should remove "//" and "/*** ***/" from
; 1. /*** Play External Memory 1, Play External Memory 1 ***/
; 2. /*** Play External Memory 2, Play External Memory 2 ***/
; 3. //CALL Mapping_Nand_Add_Check (if user want to play NAND external memory,please remark "//")
;  
; If user wants to use other type of external memory,
; the subroutine of manipulating external memory remains to be designed by user for their specific applications.
;
; 
; The external memory read subroutine must follow four rules:
; 1. The input address will be stored in R1(high address) and R0(low address) by speech decoder, 
;    so external memory subroutine must get address from R1 and R0.
; 2. The external memory must be set as byte mode.
; 3. In external memory subroutine, two consecutive bytes must be combined as one word.
; 4. The output data(word) of external memory subroutine must be put in R0.
;
;*****************************************************************************************

/*** Play External Memory 1     
.EXTERN @_LIB_F_SPI_RX_2BYTE 
.EXTERN Mapping_Nand_Add_Check
.EXTERN S1_Read_NOR_Word
.EXTERN S2_Read_NOR_Word
Play External Memory 1 ***/


Mapping_Nand_Add:
//CALL Mapping_Nand_Add_Check
RET


.GLOBAL S1_EXTERNAL_READ_WORD
S1_EXTERNAL_READ_WORD:
;********************************
;user can program code from here
;********************************

/*** Play External Memory 1
    PUSH R0  //FOR ADDRESS LOW
    PUSH R1  //FOR ADDRESS HIGH
    GET_S1_DEVICEID 
    R1 = #SPI_DEVICE
    CMP R0,R1
    IF EQ JMP @_LIB_S1_SPI_DEVICE

    R1 = #NOR_DEVICE
    CMP R0,R1
    IF EQ JMP @_LIB_S1_NOR_DEVICE

    R1 = #NAND_DEVICE
    CMP R0,R1
    IF EQ JMP @_LIB_S1_NAND_DEVICE
    
            
@_LIB_S1_NAND_DEVICE:
        POP R1  
        POP R0  
        CALL Read_Nand_Word
        JMP @_LIB_S1_EXT_END

@_LIB_S1_NOR_DEVICE:
        POP R1  
        POP R0  
        CALL S1_Read_NOR_Word
        JMP @_LIB_S1_EXT_END


@_LIB_S1_SPI_DEVICE:
        POP R1  
        POP R0  
        CALL @_LIB_F_SPI_RX_2BYTE
        JMP @_LIB_S1_EXT_END


@_LIB_S1_EXT_END:
 Play External Memory 1 ***/



RET


.GLOBAL S2_EXTERNAL_READ_WORD
.EXTERN Read_Nand_Word
S2_EXTERNAL_READ_WORD:
;********************************
;user can program code from here
;********************************

/*** Play External Memory 2
    PUSH R0  //FOR ADDRESS LOW
    PUSH R1  //FOR ADDRESS HIGH
    GET_S2_DEVICEID 
    R1 = #SPI_DEVICE
    CMP R0,R1
    IF EQ JMP @_LIB_S2_SPI_DEVICE

    R1 = #NOR_DEVICE
    CMP R0,R1
    IF EQ JMP @_LIB_S2_NOR_DEVICE

    R1 = #NAND_DEVICE
    CMP R0,R1
    IF EQ JMP @_LIB_S2_NAND_DEVICE
    
            
@_LIB_S2_NAND_DEVICE:
        POP R1  
        POP R0 
        CALL Read_Nand_Word
        JMP @_LIB_S2_EXT_END

@_LIB_S2_NOR_DEVICE:
        POP R1  
        POP R0  
        CALL S2_Read_NOR_Word
        JMP @_LIB_S2_EXT_END


@_LIB_S2_SPI_DEVICE:
        POP R1  
        POP R0 
        CALL @_LIB_F_SPI_RX_2BYTE
        JMP @_LIB_S2_EXT_END


@_LIB_S2_EXT_END:
 Play External Memory 2 ***/

RET

.GLOBAL M_EXTERNAL_READ_WORD
M_EXTERNAL_READ_WORD:
;********************************
;user can program code from here
;********************************
   
//    CALL @_LIB_F_SPI_RX_2BYTE

RET


;*****************************************************************************************
; SUBROUTINE: EXTERNAL_WRITE_WORD
; DESCRIPTION: write one block of RAM to external memory(Mode: Byte Mode).
;              SPI FLASH is the default external memory type.
;              
;              If user want to use SPI for the external memory access method, such as Melody/Speech spi application, you should remove the "//" from
;                  //.EXTERN @_LIB_F_SPI_PPGM_WORD
;                  //CALL @_LIB_F_SPI_PPGM_WORD 
;              If user wants to use other type of external memory,
;              the subroutine of manipulating external memory remains to be designed by user for their specific applications, 
;              and user needs to replace the following code with designed code
;                  //.EXTERN @_LIB_F_SPI_PPGM_WORD
;                  //CALL @_LIB_F_SPI_PPGM_WORD 
; 
; The external memory read subroutine must follow five rules:
;              R3 = #RAM_ADD (the start address of RAM)
;              R2 = #SIZE (the size of RAM)
;              R1 = #(SPI_ADD / 65536) (the high word of address of external memory)
;              R0 = #(SPI_ADD % 65536) (the low word of address of external memory)
;After writing, the new start address must be updated and stored in R1(high word of address) R0(low word of ddress)

;*****************************************************************************************
   
.EXTERN @_LIB_F_SPI_PPGM_WORD

.GLOBAL EXTERNAL_WRITE_WORD
EXTERNAL_WRITE_WORD:
;********************************
;user can program code from here
;********************************
   
//    CALL @_LIB_F_SPI_PPGM_WORD

RET





.ENDIF		;@_LIB_EXTERNAL_READ_DATA_ASM