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Ordering Mask ROM
17-2
17.1 Overview
This chapter describes the procedure for ordering mask ROM. This chapter also describes the difference in
programming when using a product that has on-chip flash memory versus a mask product, and explains how to
order ROM, etc.
17.2 Procedure for Ordering ROM
When program development with a product that has on-chip flash memory has been conducted using a flash overwrite
program (loader program), process the flash memory program by either of the following methods when ordering
the mask ROM product.
[Ordering method 1]
Refer to Fig. 17-2-1.
Delete the loader program portion (8 KB), and then recompile so that the start of the user program is located at
x’40000000. (The address x’40000008 should be used as the starting address for the user non-maskable interrupt
processing routine. This is not necessary if non-maskable interrupts are not being used, however.)
When using this method, however, the program must be relocatable.
[Ordering method 2]
Refer to Fig. 17-2-2.
Rewrite the loader program so that the user program executes without referencing the flash memory mode register
(FLMODR).
Because the execution address after a reset state is released is x’40000000, and the execution address when a non-
maskable interrupt is generated is x’40000008, place an instruction that branches to the start of the user program in
address x’40000000, and place an instruction that branches to the start of the user non-maskable interrupt processing
routine in address x’40000008.
If the user is not using non-maskable interrupt processing, the branch instruction in address x’40000008 is not
needed.
Fig. 17-2-1 ROM Ordering Method 1
Program in flash memory Program in mask ROM
x'40000000
x'40000000
x'40002000
User program
User program
Loader program
8 KB