Specifications in this manual are tentative and subject to change
Rev. E
MITSUBISHI MICROCOMPUTERS
M30245 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Functional Block Operation
12
Functional Block Operation
The M30245 group contains many functional blocks in a single chip. These blocks include ROM and RAM
to store instructions and data and the central processing unit (CPU) to execute arithmetic/logic operations.
Also included are peripheral blocks such as Timer A, serial I/O, DMAC, CRC calculation circuit, A-D con-
verter, and I/O ports.
Memory
Figure 1.5 is a memory map of the M30245 group. The address space extends the 1M bytes from address
0000016 to FFFFF16. From FFFFF16 down is ROM. For example, in the M30245MC-XXXGP, there is 128K bytes
of internal ROM from E000016 to FFFFF16. The vector table for fixed interrupts such as the reset and NMI are
mapped to FFFDC16 to FFFFF16. The starting address of the interrupt routine is stored here. The address of the
vector table for timer interrupts, etc., can be set as desired using the internal register (INTB). See the section on
interrupts for details.
From 0040016 up is RAM. For example, in the M30245MC-XXXGP, 10K bytes of internal RAM is mapped to the
space from 0040016 to 02BFF16. In addition to storing data, the RAM also stores the stack used when calling
subroutines and when interrupts are generated.
The SFR area is mapped to 0000016 to 003FF16. This area accommodates the control registers for peripheral
devices such as I/O ports, A-D converter, serial I/O, and timers, etc. Any part of the SFR area that is not occupied
is reserved and cannot be used for other purposes.
The special page vector table is mapped to FFE0016 to FFFDB16. If the starting addresses of subroutines or the
destination addresses of jumps are stored here, subroutine call instructions and jump instructions can be used as
2-byte instructions, reducing the number of program steps.
In memory expansion mode and microprocessor mode, some memory areas are reserved and cannot be used.
For example, in the M30245MC-XXXGP, the following areas cannot be used.
The space between 02C0016 and 03FFF16 (Memory expansion and microprocessor modes)
The space between D000016 and E000016 (Memory expansion mode)
Figure 1.5. Memory map
0000016
YYYYY16
FFFFF16
0040016
0400016
XXXXX16
D000016
External area
Internal ROM area
SFR area
For details, see
Table 1.6 to 1.13
Internal RAM area
Internal reserved
area (Note 1)
Internal reserved
area (Note 2)
FFE0016
FFFDC16
FFFFF16
Note 1: Cannot be used during memory expansion and microprocessor modes
Note 2: Cannot be used in memory expansion mode.
Undefined instruction
Overflow
BRK instruction
Address match
Single step
Watchdog timer
Reset
Special page
vector table
DBC
NMI
M30245FCGP
02BFF16
E000016
M30245MC-XXXGP
02BFF16
E000016
M30245M8-XXXGP
F000016
017FF 16
Address XXXXX16
Type No.
Address YYYYY16