M37212 Mitsubishi, M37212 Datasheet - Page 27

• Manufacturer Part Number: M37212
• Description: SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER
• Manufacturer: Mitsubishi

8.5 SERIAL I/O
This microcomputer has a built-in serial I/O which can either transmit
or receive 8-bit data serially in the clock synchronous mode.
The serial I/O block diagram is shown in Figure 8.5.1. The synchro-
nous clock I/O pin (S
(S
Bit 3 of the serial I/O mode register (address 00DC
the synchronous clock is supplied internally or externally (from the
S
whether f(X
for serial I/O, set the corresponding bit of the port P2 direction regis-
ter (address 00C5
Rev. 1.0
Fig. 8.5.1 Serial I/O Block Diagram
CLK
IN
) also functions as port P4.
pin). When an internal clock is selected, bits 1 and 0 select
Note : When the data is set in the serial I/O register (address 00DD
S
OUT(/IN)
IN
S
) or f(X
X
CLK
S
IN
IN
16
CIN
) to “0.”
CLK
) is divided by 4, 16, 32, or 64. To use S
P4
P4
), data output pin (S
SM3
SM3
1
0
1/2
latch
latch
Synchronization circuit
1/2
SM6
OUT
M37212M4/M8–XXXSP, M37212M6–XXXSP/FP
), and data input pin
SM5 : LSB
16
) selects whether
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER
Serial I/O shift register (8)
IN
pin
Serial I/O counter (8)
SM2
MSB
S
The operation of the serial I/O is described below. The operation of
the serial I/O differs depending on the clock source; external clock or
internal clock.
(Address 00DD
16
), the register functions as the serial I/O shift register.
Frequency
divider
(See note)
1/4
1/8
8
16
with ON-SCREEN DISPLAY CONTROLLER
1/16
)
SM1
SM0
MITSUBISHI MICROCOMPUTERS
Data bus
M37212EFSP/FP
SM : Serial I/O mode register
Serial I/O interrupt
request
Selection gate :
Connected to black
colored side at reset.
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