M30622 Mitsubishi, M30622 Datasheet - Page 33

• Manufacturer Part Number: M30622
• Description: SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
• Manufacturer: Mitsubishi

Bus Control
Bus Control
Table 1.12.1. External areas specified by the chip select signals
Note 1: In M30623(80-pin package), the chip select signals have no corresponding external pin.
Note 2: The M16C/62T Group is not guaranteed to operate in memory expansion and microprocessor
The following explains the signals required for accessing external devices and software waits. The signals
required for accessing the external devices are valid when the processor mode is set to memory expansion
mode and microprocessor mode. The software waits are valid in all processor modes.
M30623(80-pin package), in which the BYTE pin is connected to the CNV
width can be used 8 bits.
M16C/62T group is not guaranteed to operate in memory expansion and microprocessor modes.
Memory space
expansion mode
(1) Address bus/data bus
(2) Chip select signalIn (In M30623(80-pin package), the chip select signals have no corresponding
external pin.)
Normal mode
(PM15,14=0,0)
Expansion
mode 1
(PM15,14=1,0)
Expansion
mode 2
(PM15,14=1,1)
The address bus consists of the 20 pins A
The data bus consists of the pins for data I/O. When the BYTE pin is “H”, the 8 ports D
as the data bus. When BYTE is “L”, the 16 ports D
When a change is made from single-chip mode to memory expansion mode, the value of the address
bus is undefined until external memory is accessed.
The chip select signal is output using the same pins as P4
register (address 0008
select control register is valid in memory expansion mode and microprocessor mode. In single-chip
mode, P4
register.
In microprocessor mode, only CS0 outputs the chip select signal after the reset state has been can-
celled. CS1 to CS3 function as input ports. Figure 1.12.1 shows the chip select control register.
The chip select signal can be used to split the external area into as many as four blocks. Tables 1.12.1
and 1.12.2 show the external memory areas specified using the chip select signal.
modes.
_______
4
to P4
Memory expansion
mode
Memory expansion
mode
Memory expansion
mode
Microprocessor
mode
Microprocessor
mode
Microprocessor
mode
_______
Processor mode
7
function as programmable I/O ports regardless of the value in the chip select control
16
) set each pin to function as a port or to output the chip select signal. The chip
_______
(512K bytes
(512K bytes
(1008K bytes)
+ 256K bytes)
(640K bytes)
(832K bytes)
(816K bytes)
30000
30000
04000
04000
40000
40000
CFFFF
CFFFF
BFFFF
FFFFF
FFFFF
FFFFF
CS0
16
16
16
16
16
16
0
16
16
16
16
16
16
to A
to
to
to
to
to
to
33
8)
7
19
for accessing the 1M bytes of address space.
0
to D
(32K bytes)
(96K bytes)
28000
28000
2FFFF
3FFFF
CS1
15
4
Chip select signal
to P4
function as the data bus.
16
16
16
16
to
to
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
7
. Bits 0 to 3 of the chip select control
SS
(128K bytes)
08000
pin, and the external data bus
27FFF
CS2
16
Mitsubishi microcomputers
16
to
M16C / 62T Group
0
(16K bytes)
to D
04000
07FFF
CS3
7
function
16
16
to