在MAX-IDE中自動初始化數(shù)據(jù)段

;; This is the free-running code, executed on subsequent power-ups, that copies
;; values from the flash back into their proper data segment locations.

move DP[0], #0F000h ; Source: Flash location 7000h
move BP, #0 ; Dest: Start of RAM
move Offs, #0
move LC[0], #100h ; Copy 256 words
lcall UROM_copyBuffer

jump main

;; This is the first-pass code. A bit of a trick here; because MAX-IDE enters
;; and exits the loader separately when loading the code and data segment files,
;; the application is allowed to execute briefly before the data segment file
;; has been loaded. The first four lines under copyFlash ensure that the
;; application waits for MAX-IDE to load the data segment file before continuing.

copyToFlash:
move DP[0], #0h ; Wait for flag variable to be loaded by MAX-IDE.
move Acc, @DP[0] ; Note that this will reset the application; the
cmp #1234h ; data segment is not loaded while the application
jump NE, copyToFlash ; is still running.

move DP[0], #0 ; Start of RAM variable area
move A[4], #7000h ; Location in flash to write to
move LC[0], #100h ; Store 256 words in flash 7000h-70FFh

copyToFlash_loop:
move DP[0], DP[0] ; Refresh the data pointer to read values correctly,
; because calling UROM_flashWrite changes memory
; contexts and affects the cached @DP[0] value
move A[0], A[4] ; Location to write
move A[1], @DP[0]++ ; Value to write (taken from RAM)
lcall UROM_flashWrite
move Acc, A[4]
add #1
move A[4], Acc
djnz LC[0], copyToFlash_loop

main:
move PD0, #0FFh ; Set all port 0 pins to output
move PO0, #000h ; Drive all port 0 pins low (LEDs off)

move DPC, #1Ch ; Set pointers to word mode
move DP[0], #varA
move Acc, @DP[0]
cmp #1234h ; Verify that the variable is set correctly
jump NE, fail

pass:
move PO0, #55h
sjump $

fail:
sjump $

segment data

org 0000h

varA:
dw 1234h

org 00FFh

varB:
dw 5678h

end

結(jié)論
MAX-IDE提供的程序段和數(shù)據(jù)段工具能夠在數(shù)據(jù)存儲器中自動聲明變量地址，以起始值初始化這些變量。可以利用應(yīng)用程序在閃存中緩存這些變量，必要時恢復(fù)它們。這種方法允許基于匯編的應(yīng)用程序使用MAX-IDE提供的數(shù)據(jù)段自動裝載功能，無論微控制器是否連接JTAG調(diào)試器，都能保持工作。