电子产品世界

;; 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

结论
MAX-IDE提供的程序段和数据段工具能够在数据存储器中自动声明变量地址，以起始值初始化这些变量。可以利用应用程序在闪存中缓存这些变量，必要时恢复它们。这种方法允许基于汇编的应用程序使用MAX-IDE提供的数据段自动装载功能，无论微控制器是否连接JTAG调试器，都能保持工作。

关键词： 数据 初始 自动 MAX-IDE