TMP86CH49FG Datasheet, PDF (188/252 Pages) Toshiba Semiconductor – 8 Bit Microcontroller

14. Synchronous Serial Interface (SIO1)
14.3 Function
TMP86CH49FG
SIO1CR<SIOS>
SIO1SR<SIOF>
SIO1SR<SEF>
Reading received data
Writing transmit data
Clearing SIOS
Start shift
operation
Start shift
operation
Start shift
operation
SCK1 pin output
SO1 pin
SI1 pin
INTSIO1
interrupt
request
SIO1SR<TXF>
A7 A6 A5 A4 A3 A2 A1 A0 B7 B6 B5 B4 B3 B2 B1 B0 C7 C6 C5 C4 C3 C2 C1 C0
D7 D6 D5 D4 D3 D2 D1 D0 E7 E6 E5 E4 E3 E2 E1 E0 F7 F6 F5 F4 F3 F2 F1 F0
SIO1TDB
A
B
C
SIO1SR<RXF>
Writing transmit
data A
Writing transmit Writing transmit
data B
data C
SIO1RDB
D
E
F
Reading received
data D
Reading received
data E
Reading received
data F
Figure 14-14 Example of External Clock and MSB Transmit/Receive Mode
(4) Transmit/receive error processing
Transmit/receive errors occur on the following situation. Corrective action is different, which
errors occur transmits or receives.
(a) Transmit errors
Transmit errors occur on the following situation.
• Shift operation starts before writing next transmit data to SIO1TDB in external clock op-
eration.
If transmit errors occur during transmit operation, SIO1SR<TXERR> is set to “1” im-
mediately after starting shift operation. And INTSIO1 interrupt request is generated af-
ter all of the 8-bit data has been received.
If shift operation starts before writing data to SIO1TDB after SIO1CR<SIOS> is set to
“1”, SIO1SR<TXERR> is set immediately after starting shift operation. And INTSIO1
interrupt request is generated after all of the 8-bit data has been received.
SO1 pin is kept in high level when SIO1SR<TXERR> is set to “1”. When transmit error
occurs, transmit operation must be forcibly stop by writing SIO1CR<SIOINH> to “1”
after the received data is read from SIO1RDB. In this case, SIO1CR<SIOS>, SIO1SR
register, SIO1RDB register and SIO1TDB register are initialized.
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