M37702E6BFS Renesas Electronics America, M37702E6BFS Datasheet - Page 498

• Manufacturer Part Number: M37702E6BFS
• Description: EPROM MCU/8BIT CMOS EMULATION CH
• Manufacturer: Renesas Electronics America

Specifications of M37702E6BFS

• Accessory Type: Emulator EPROM MCU
• For Use With/related Products: 7702
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPENDIX
Appendix 6. Q & A
21–52
Q
A
XXXX
If the processor mode is switched as described above by using the processor mode bits, the
mode is switched simultaneously when the cycle to write to the processor mode bits is completed.
Then, the program counter indicates the address next to the address (address XXXX
contains the write instruction for the processor mode bits. Additionally, access to the internal
ROM area is disabled. However, since the instruction queue buffer can prefetch up to three
instructions, the address in the external ROM area and is accessed first after the mode is
switched is one of XXXX
XXXX
following by software.
If the processor mode is switched as described below by using the processor mode bits (bits 1
and 0 at address 5E
Single-chip mode
Memory expansion mode
16
Write the write instruction for the processor mode bits and next instructions (at least three
bytes) at the same addresses both in the internal ROM and external ROM areas. (See
below.)
Transfer the write instruction for the processor mode bits to an internal RAM area and make
a branch to there in order to execute the write instruction. After that, make a branch to the
program address in the external ROM area. (Contents of the instruction queue buffer is
initialized by a branch instruction.)
16
:
:
LDM. B #00000010B, PMR
NOP
NOP
NOP
:
+ 3 in the internal ROM area can be executed. To prevent this problem, process the
Internal ROM area
16
) during program execution, is there any precaution in software?
Microprocessor mode
16
+ 1 to XXXX
Microprocessor mode
7702/7703 Group User’s Manual
16
+ 4. The instructions at addresses XXXX
At least
three
bytes
XXXX
16
:
:
LDM. B #00000010B, PMR
NOP
NOP
NOP
:
:
External ROM area
Processor mode
16
16
+ 1 to
) that