Cautions On Rom Correction - NEC PD78076 User Manual

Pd78078 series; pd78078y series 8-bit single-chip microcontrollers

Table of Contents

26.7 Cautions on ROM Correction

(1) Address values set in correction address registers 0 and 1 (CORAD0, CORAD1) must be addresses where

instruction codes are stored.

(2) Correction address registers 0 and 1 (CORAD0, CORAD1) should be set when the correction enable flag

(COREN0, COREN1) is 0 (when the correction branch is in disabled state). If address is set to CORAD0

or CORAD1 when COREN0 or COREN1 is 1 (when the correction branch is in enabled state), the correction

branch may start with the different address from the set address value.

(3) Do not set the address value of instruction immediately after the instruction that sets the correction enable

flag (COREN0, COREN1) to 1, to correction address register 0 or 1 (CORAD0, CORAD1) ; the correction

branch may not start.

(4) Do not set the address value in table area of table reference instruction (CALLT instruction) (0040H to

007FH), and the address value in vector table area (0000H to 003FH) to correction address registers 0 and

1 (CORAD0, CORAD1).

(5) Do not set two addresses immediately after the instructions shown below to correction address registers

0 and 1 (CORAD0, CORAD1). (that is, when the mapped terminal address of these instructions is N, do

not set the address values of N+1 and N+2.)

• BR $addr16

CHAPTER 26 ROM CORRECTION