UPD78F9222MC(T)-5A4-A NEC, UPD78F9222MC(T)-5A4-A Datasheet - Page 202

• Manufacturer Part Number: UPD78F9222MC(T)-5A4-A
• Description: 8BIT MCU, 4K FLASH, 256B RAM, 78F9222
• Manufacturer: NEC

Specifications of UPD78F9222MC(T)-5A4-A

• Controller Family/series: UPD78
• No. Of I/o's: 17
• Ram Memory Size: 256Byte
• Cpu Speed: 10MHz
• No. Of Timers: 4
• No. Of: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 4KB
• Oscillator Type: External, Internal

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(d) Continuous transmission
The next transmit data can be written to transmit buffer register 6 (TXB6) as soon as transmit shift register 6
(TXS6) has started its shift operation. Consequently, even while the INTST6 interrupt is being serviced after
transmission of one data frame, data can be continuously transmitted and an efficient communication rate
can be realized. In addition, the next transmit data can be written to the TXB6 register without having to wait
for the transmission time of one data frame, by confirming bit 0 (TXSF6) of asynchronous serial interface
transmission status register 6 (ASIF6) after a transmission completion interrupt has occurred.
To transmit data continuously, be sure to reference the ASIF6 register to check the transmission status and
whether the TXB6 register can be written, and then write the data.
For the continuous transmission procedure, refer to Figure 11-16 Example of Continuous Transmission
Processing Flow.
Cautions 1. Use the value of the TXBF flag to judge whether continuous transmission is possible.
The communication status can be checked using the TXSF6 flag.
Caution To initialize the transmission unit upon completion of continuous transmission, be
Caution To transmit data continuously, write the first transmit data (first byte) to the TXB6
2.
TXBF6
TXSF6
0
1
0
1
Do not write the next transmit data, by making a judgment only by the fact that the
TXSF6 flag has been set to 1.
When the interface is used for LIN communication operation, the continuous
transmission function cannot be used. Make sure that asynchronous serial interface
transmission status register 6 (ASIF6) is 00H before writing transmit data to transmit
buffer register 6 (TXB6).
sure to check that the TXSF6 flag is “0” after generation of the transmission
completion interrupt, and then execute initialization.
while the TXSF6 flag is “1”, the transmit data cannot be guaranteed.
register. Be sure to check that the TXBF6 flag is “0”. If so, write the next transmit
data (second byte) to the TXB6 register. If data is written to the TXB6 register while
the TXBF6 flag is “1”, the transmit data cannot be guaranteed.
Writing enabled
Writing disabled
Transmission is completed.
Transmission is in progress.
CHAPTER 11 SERIAL INTERFACE UART6
User’s Manual U16898EJ5V0UD
Writing to TXB6 Register
Transmission Status
If initialization is executed