HD614P080S-------------------------------------------------------------
Table 7. Serial Mode Register
SMR
Bit 3
o Used
as
R40
port
input/output
pin
Used
as
SCK
input/output
pin
SMR
Transfer Clock
Bit 2
Prescaler
System Clock
Bit 1
Bit
0
R4o/SCK
Port
Clock Source
Divide
Divide
Ratio
Ratio
0
0
0
S-CK
Prescaler
+
2048
+4096
Output
0
0
1
SCK
Output
Prescaler
512
+ 1024
0 1
0
SCK
Prescaler
128
Output
256
0 1
1
SCK
Output
Prescaler
32
64
1
0
0
SCK
Prescaler
8
Output
16
1
0
1
SCK
Prescaler
2
Output
4
1
1
0
SCK
System
Output
Clock
-
1
1
1
1
SCK
External
Input
Clock
-
-
(In
the
case
ofSMR
Bit3=
1)
Transfer Clock
Serial
Output
Data
Serial Input Data
Latch Timing
I I I I I I I I
Fig.
10
Serial Interface I/O Timing Chart
• SERIAL Interrupt Request Flag (lFS:
$003,
0)
The SERIAL Interrupt Request Flag will be set after the
eight transfer clock signals
or
transmit/receive discontinued
operation
by
resetting the Octal Counter.
• SERIAL Interrupt Mask
OMS:
$003,
1)
The SERIAL Interrupt Mask masks
the
interrupt request.
Table
8.
SERIAL
Interrupt
Request Flag
SERIAL
Interrupt
Request Flag
Interrupt
Request
o
No
Yes
274
Table 9. SERIAL
Interrupt
Mask
SERIAL
Interrupt
Mask
Interrupt
Request
o
Enable
Disable
(masks)
• Selection of
the
Operation Mode
Table
10 shows the operation mode
of
the serial interface.
Select a combination
of
the value in the Port Mode Register and
the
Serial Mode Register according
to
Table 10.
Initialize the serial interface by the Write Signal to the
Serial Mode Register, when the Operation Mode
is
changed.
• Operating State
of
Serial Interface
The serial interface has 3 operating states as shown in Fig. 11.
The serial interface gets into "STS waiting state"
by
2 ways:
one way
is
to
change the operation mode by changing the data
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