M37281EKSP Datasheet, PDF (14/172 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER and ON-SCREEN DISPLAY CONTROLLER

M37281MAH–XXXSP,M37281MFH–XXXSP,M37281MKH–XXXSP, M37281EKSP
8.2.10 Expansion ROM (only M37281MKH-
XXXSP/M37281EKSP)
The M37281MKH-XXXSP/M37281EKSP can use 5-bank (total 20K
bytes) expansion ROM (4K bytes each bank) by setting the bank
register.
The expansion ROM is assigned to address 1B00016 to 1FFFF16.
The contents of each bank in the expansion ROM are read by setting
the bank register and accessing addresses 100016 to 1FFF16. As the
expansion ROM is not programmable, use it as data-dedicated area.
When using the expansion ROM area, the internal ROM at addresses
100016 to 1FFF16 (extra area) is not also programmable.
Notes 1: When using the expansion ROM (BK7 = “1”), the ROM correction
function do not operate for addresses 100016 to 1FFF16.
2: When using the emulator MCU (M37281ERSS), as addresses 100016
to FFFF16 can be emulated by setting bit 7 of the bank control regis-
ter to “0,” the expansion ROM cannot be used. Addresses 200016 to
FFFF16 can be emulated by setting it to “1.” The data in specified
area by the bank selection bits can be read by accessing addresses
100016 to 1FFF16.
3: When using the emulator MCU, the expansion ROM and the extra
area cannot be emulated by setting bit 7 of the bank control register
to “1.” Therefore, write the data to this area before using.
4: For the M37281MKH-XXXSP, fix bit 7 of the bank control register to
“1.” For M37281MAH-XXXSP and M37281MFH-XXXSP, fix the ad-
dress 00ED16 to “0016.”
Bank Control Register
b7 b6 b5 b4 b3 b2 b1 b0
00
Bank control register (BK) [Address 00ED16]
B
Name
Functions
0 Bank
Bank number is selected (bank 11 to 15)
to selection bits
3 (BK0 to BK3)
4, 5 Fix these bits to “0.”
After reset R W
0
RW
0
RW
6, 7 Bank control
bits
(BK6, BK7)
b7 b6 Bank ROM Address 100016 level
access
0 ✕ Not used ^{Read out from extra area}
(programmable)
1 0 Used
Read out the data
from area specified by
the bank selection bits
1 1 Used
Read out from extra area
(data-dedicated)
0
RW
Fig. 8.2.3 Bank Control Register
Rev.1.01 2003.07.16 page 14 of 170