M30622 Mitsubishi, M30622 Datasheet - Page 35

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

Bus Control
Table 1.12.4. Microcomputer status in ready state (Note 1)
Note 1: The RDY signal cannot be received immediately prior to a software wait.
Note 2: In M30623(80-pin package), CS signals have no corresponding external pin.
Figure 1.12.2. ALE signal and address/data bus
Oscillation
R/W signal, address bus, data bus, CS
ALE signal, HLDA, programmable I/O ports
Internal peripheral circuits
(4) ALE signal
________
(5) The RDY signal
RDY is a signal that facilitates access to an external device that requires long access time. As shown in
Figure 1.12.3, if an “L” is being input to the RDY at the BCLK falling edge, the bus turns to the wait state. If
an “H” is being input to the RDY pin at the BCLK falling edge, the bus cancels the wait state. Table 1.12.4
shows the state of the microcomputer with the bus in the wait state, and Figure 1.12.3 shows an example in
which the RD signal is prolonged by the RDY signal.
The RDY signal is valid when accessing the external area during the bus cycle in which bits 4 to 7 of the
chip select control register (address 0008
bits 4 to 7 of the chip select control register (address 0008
as in non-using.
The ALE signal latches the address when accessing the multiplex bus space. Latch the address when the
ALE signal falls.
D
___
0
/A
________
0
A
to D
8
When BYTE pin = “H”
to A
________
____
________
ALE
7
__________
/A
19
7
Note 1: Floating when reading.
Note 2: When multiplexed bus for the entire space is selected, these are I/O ports.
Note 3: In M30623 (80-pin package), P1
Address
So, M30623 (80-pin package) can operate only when BYTE pin = “H” (the width of external
data bus is 16-bit).
Item
Address (Note 2)
________
Data (Note 1)
_____
_____
________
16
________
) are set to “0”. The RDY signal is invalid when setting “1” to all
0
35
to P1
On
Maintain status when RDY signal received
On
7
D
0
which are in common with D8 to D15 are available.
16
/A
), but the RDY pin should be treated as properly
1
A
to D
9
When BYTE pin = “L”
to A
________
ALE
7
/A
A
19
0
8
________
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
________
Status
Address
Mitsubishi microcomputers
Address
Address
M16C / 62T Group
Data (Note 1)