559
CHAPTER 26 ROM CORRECTION
26.1 ROM Correction Functions
The
µ
PD78078, 78078Y 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-78001-R-A, IE-78K0-NS).
26.2
ROM Correction Configuration
The ROM correction is executed by the following hardware.
Table 26-1. ROM Correction Configuration
Item
Configuration
Register
Correction address registers 0 and 1 (CORAD0, CORAD1)
Control register
Correction control register (CORCN)
Figure 26-1 shows a block diagram of the ROM correction.
Figure 26-1. Block Diagram of ROM Correction
Remark
n = 0, 1
Match
CORENn CORSTn
Program counter (PC)
Comparator
Correction address
register (CORADn)
Internal bus
Correction control register
Correction branch request
signal (BR !7FDH)
Summary of Contents for PD78076
Page 2: ...2 MEMO ...
Page 12: ...12 MEMO ...
Page 48: ...48 MEMO ...
Page 64: ...64 MEMO ...
Page 82: ...82 MEMO ...
Page 100: ...100 MEMO ...
Page 130: ...130 MEMO ...
Page 180: ...180 MEMO ...
Page 222: ...222 MEMO ...
Page 248: ...248 MEMO ...
Page 288: ...288 MEMO ...
Page 308: ...308 MEMO ...
Page 364: ...364 MEMO ...
Page 494: ...494 MEMO ...
Page 526: ...526 MEMO ...
Page 544: ...544 MEMO ...
Page 558: ...558 MEMO ...
Page 580: ...580 MEMO ...
Page 596: ...596 MEMO ...
Page 598: ...598 MEMO ...
Page 626: ...626 MEMO ...