tmp88cu74 TOSHIBA Semiconductor CORPORATION, tmp88cu74 Datasheet - Page 101

• Manufacturer Part Number: tmp88cu74
• Description: Cmos 8-bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

SCK
SIOS
SIOF
SEF
SI0 pin
INTSBI interrupt
request
SBIDBR
0
pin (output)
c.
8-bit transmit/receive mode
After the data is written, set the SIOS to “1” to start transmitting/receiving. When
transmitting, the data is output from the SO0 pin on the leading edges in
synchronous with the serial clock, starting from the least significant bit (LSB).
When receiving, the data is input to the SI0 pin on the trailing edges of the serial
clock. 8-bit data is transferred from the shift register to the SBIDBR, and the
INTSBI interrupt request occurs. The interrupt service program reads the
received data from the data buffer register and writes data to be transmitted. The
SBIDBR is used for both transmitting and receiving. Transmitted data should
always be written after received data is read.
received data is read and next data is written.
the serial clock provided externally, received data is read and transmitted data is
written before new shift operation is executed. The maximum transfer speed
when the external clock is used is determined by the delay time between the time
when an interrupt request is generated and the time when received data is read
and transmitted data is written.
output until the falling edge of the
interrupt service program or setting the SIOINH to “1”. When the SIOS is cleared,
received data is transferred to the SBIDBR in complete blocks. The
transmit/receive mode ends when the transfer is complete. In order to confirm if
data is surely transmitted/received by the program, set the SIOF (bit 3 in SBISR)
to be sensed. The SIOF becomes “0” after transmitting/receiving is complete.
When the SIOINH is set, transmitting/receiving data stops. The SIOF turns “0”.
Note: When the transfer mode is switched, the SBIDBR contents are lost. In case
Set a control register to a transmit/receive mode and write data to the SBIDBR.
When the internal clock is used, automatic-wait function is initiated until
When the external clock is used, since the shift operation is synchronized with
When the transmit is started, the same value as the final bit of the last data is
Transmitting/receiving data is ended by cleaning the SIOS to “0” by the INTSBI
Figure 2.10.23 Receive Mode (Example: Internal Clock)
a
0
that the mode needs to be switched, conclude transmitting/receiving data by
clearing the SIOS to “0”, read the last data, and then switch the transfer mode.
a
1
a
2
a
3
88CU74-101
a
4
a
5
a
6
SCK
a
Read received data
7
b
after the SIOF goes “1”.
0
a
b
1
b
2
Clear SIOS
b
3
b
4
b
5
Read received data
b
6
TMP88CU74
2007-10-19
2003-02-17
b
7
b