M37736M4BXXXGP Datasheet, PDF (7/32 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

PRELIMINARY _{NSootimcee: pTahriasmisentroict} ^{alimfinitsalasrpeescuifbicjeactitotno. change.}
MITSUBISHI MICROCOMPUTERS
M37736M4BXXXGP
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
ROM AREA MODIFICATION FUNCTION
The internal ROM size and its address area of the M37736M4BXXXGP
can be modified by the memory allocation control register’s bit 0 shown
in Figure 3.
Figure 5 shows the memory allocation in which the internal ROM
size and its address area are modified.
Make sure to write data in the memory allocation control register as
the flow shown in Figure 4.
This ROM area modification function is valid in memory expansion
mode and single-chip mode.
Table 1 shows the relationship between memory allocation selection
___
___
bits and address corresponding to chip-select signals CS0 and CS1 in
the external bus mode B.
When ordering a mask ROM, Mitsubishi Electric corp. produces the
mask ROM using the data within 32 Kbytes (addresses 00800016 –
00FFFF16). It is regardless of the selected ROM size (refer to MASK
ROM ORDER CONFIRMATION FORM.) Therefore, program “FF16”
to the addresses out of the selected ROM area in the EPROM which
you tender when ordering a mask ROM.
Address 00FFFF16 of this microcomputer corresponds to the lowest
address of the EPROM which you tender.
76543210
Address
ML0 Memory allocation control register
6316
Memory allocation selection bit
ROM size
(ROM area)
0 : 32 Kbytes (addresses 00800016 – 00FFFF16)
1 : 16 Kbytes (addresses 00C00016 – 00FFFF16)
Note. Write to the memory allocation control register as the flow shown in Figure 4.
Fig. 3 Bit configuration of memory allocation control register
Writing data “5516” (LDM instruction)
Writing data “0016” or “0116” (LDM instruction)
Next instruction
ML0 selection bit
• How to write in memory allocation control register
Fig. 4 How to write data in memory allocation control register
7