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User’s Manual U15798EJ2V0UD
CHAPTER 22 ROM CORRECTION
22.1 ROM Correction Functions
In the
µ
PD780344, 780354, 780344Y, 780354Y Subseries, part of a program in the mask ROM or flash memory
can be released with a program in the internal expansion RAM.
Instruction bugs found in the mask ROM or flash memory can be avoided, and program flow can be changed by
using the ROM correction function.
ROM correction can correct two places (max.) of the internal ROM or on-chip flash memory (program).
Caution ROM correction cannot be emulated by the in-circuit emulator (IE-78K0-NS, IE-78K0-NS-A).
22.2 ROM Correction Configuration
ROM correction consists of the following hardware.
Table 22-1. ROM Correction Configuration
Item
Configuration
Registers
Correction address registers 0 and 1 (CORAD0, CORAD1)
Control register
Correction control register (CORCN)
Figure 22-1 shows a block diagram of ROM correction.
Figure 22-1. ROM Correction Block Diagram
Remark
n = 0, 1
Match
CORENn CORSTn
Program counter (PC)
Comparator
Correction address
register n (CORADn)
Internal bus
Correction control register
Correction branch request
signal (BR !F7FDH)
Содержание mPD780344 Series
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