NEC uPD78053 Manuale Utente
537
Match
CORENn CORSTn
Program counter (PC)
Comparator
Correction address
register (CORADn)
register (CORADn)
Internal bus
Correction control register
Correction branch request
signal (BR !7FDH)
signal (BR !7FDH)
CHAPTER 25 ROM CORRECTION
25.1 ROM Correction Functions
The
µ
PD78058, 78058Y subseries can replace part of a program in the mask ROM with a program in the internal
expansion RAM.
Instruction bugs found in the mask ROM can be avoided, and program flow can be changed by using the ROM
correction.
The ROM correction can correct two places (max.) of the internal ROM (program).
Caution
The ROM correction cannot be emulated by the in-circuit emulator (IE-78000-R, IE-78000-R-A,
IE-78K0-NS, IE-78001-R-A).
25.2 ROM Correction Configuration
The ROM correction is executed by the following hardware.
Table 25-1. ROM Correction Configuration
Item
Configuration
Register
Correction address registers 0 and 1 (CORAD0, CORAD1)
Control register
Correction control register (CORCN)
Figure 25-1 shows a block diagram of the ROM correction.
Figure 25-1. Block Diagram of ROM Correction
Remark
n = 0, 1