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Table 8.2 Processor Mode and Port Function
Access all CS Areas using
the Separate Bus
Single-
Chip Mode
Memory Expansion Mode/ Microprocessor Mode
Memory Expansion Mode
Data Bus Width
"012", "102""002"
"112"(1)
Access all
external space with
8-bit data bus
NOTES:
1. The PM05 and PM04 bits cannot be set to "112" (access all CS areas using multiplexed bus) in microprocessor mode
because the microcomputer starts operation using the separate bus after reset.
When the PM05 and PM04 bits are set to "112" in memory expansion mode, the microcomputer accesses 64-Kbyte
memory space per chip-select using the address bus .
2. These ports become address buses when accessing space using the separate bus.
3. The PM15 and PM14 bits in the PM1 register determines which pin outputs the ALE signal. The PM02 bit in the PM0
register selects either "WRL,WRH" or "BHE,WR" combination.
P56 provides an indeterminate output when the PM15 and PM14 bits to "002" (no ALE). It cannot be used as an I/O port.
4. The PM11 and PM10 bits in the PM1 register determine the CS signal and address bus.
PM05 to
PM04 Bits in
PM0 Register
CS (Chip-select signal) or Address bus (A23)
(Refer to 8.2 Bus Control for details)(4)
Outputs RD, WRL, WRH and BCLK or outputs RD, BHE, WR and BCLK
(Refer to 8.2 Bus Control for details)(3)
P00 to P07
P10 to P17
Data bus
D0 to D7
I/O port
P20 to P27
I/O port
Address bus
Data bus(2)
A0/D0 to A7/D7
I/O port
P30 to P37
I/O port
Address bus/
Data bus(2)
A8/D8 to A15/D15
P40 to P43
I/O port
P44 to P46
I/O port
P47
I/O port
P50 to P53
I/O port
P54
I/O port
P55
I/O port
P56
I/O port
P57
I/O port
HOLD
ALE (3)
RDY
Access CS1 or CS2 using
the Multiplexed Bus
Access All Other CS Areas using
the Separate Bus
Data bus
D0 to D7
Data bus
D0 to D7
Data bus
D0 to D7
Address bus
Data bus(2)
A0/D0 to A7/D7
Address bus
A0 to A7
Address bus
A0 to A7
Address bus
Data bus
A0/D0 to A7/D7
Address bus
Data bus
A0/D0 to A7/D7
Address bus
A8 to A15
Address bus
A8 to A15
Address bus
A8 to A15
Address bus
A8 to A15
Address bus
A16 to A19
Address bus
A16 to A19
Address bus
A16 to A19
Address bus
A16 to A19
Data bus
D8 to D15
Data bus
D8 to D15
Address bus/
Data bus
A8/D8 to A15/D15
Access all CS Areas using
the Multiplexed Bus
Access one or more
external space with
16-bit data bus
Access all
external space with
8-bit data bus
Access one or more
external space with
16-bit data bus
Access all
external space with
8-bit data bus
Access one or more
external space with
16-bit data bus
CS (Chip-select signal) or Address bus (A20 to A22)
(Refer to 8.2 Bus Control for details)(4)
HDLA (3)
ALE (3)
Processor
Mode