UPD78F0890GK(A)-GAJ-AX NEC, UPD78F0890GK(A)-GAJ-AX Datasheet - Page 342

• Manufacturer Part Number: UPD78F0890GK(A)-GAJ-AX
• Description: 8BIT MCU, 128K FLASH, 7K RAM, LQFP
• Manufacturer: NEC

Specifications of UPD78F0890GK(A)-GAJ-AX

• Controller Family/series: UPD78F
• No. Of I/o's: 55
• Ram Memory Size: 7KB
• Cpu Speed: 20MHz
• No. Of Timers: 10
• No. Of Pwm: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 128KB
• Oscillator Type: External, Internal

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(d) Continuous transmission
The next transmit data can be written to transmit buffer register 6n (TXB6n) as soon as transmit shift register
6 (TXS6n) has started its shift operation. Consequently, even while the INTST6n 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 TXB6n register can be efficiently written twice (2 bytes) without having
to wait for the transmission time of one data frame, by reading bit 0 (TXSF6n) of asynchronous serial
interface transmission status register 6n (ASIF6n) when the transmission completion interrupt has occurred.
To transmit data continuously, be sure to reference the ASIF6n register to check the transmission status and
whether the TXB6n register can be written, and then write the data.
The communication status can be checked using the TXSF6n flag.
Cautions 1. The TXBF6n and TXSF6n flags of the ASIF6n register change from “10” to “11”, and to
Caution To transmit data continuously, write the first transmit data (first byte) to the
Cautions 1. To initialize the transmission unit upon completion of continuous
Remark n = 0, 1
TXBF6n
TXSF6n
2. When the device is used in LIN communication operation, the continuous
0
1
0
1
2. During continuous transmission, an overrun error may occur, which
TXB6n register. Be sure to check that the TXBF6n flag is “0”. If so, write the
next transmit data (second byte) to the TXB6n register. If data is written to
the TXB6n register while the TXBF6n flag is “1”, the transmit data cannot be
guaranteed.
“01” during continuous transmission. To check the status, therefore, do not use a
combination of the TXBF6n and TXSF6n flags for judgment. Read only the TXBF6n
flag when executing continuous transmission.
transmission function cannot be used. Make sure that asynchronous serial interface
transmission status register 6n (ASIF6n) is 00H before writing transmit data to
transmit buffer register 6n (TXB6n).
transmission, be sure to check that the TXSF6n flag is “0” after
generation of the transmission completion interrupt, and then execute
initialization. If initialization is executed while the TXSF6n flag is “1”, the
transmit data cannot be guaranteed.
means that the next transmission was completed before execution of
INTST6n interrupt servicing after transmission of one data frame.
overrun error can be detected by developing a program that can count the
number of transmit data and by referencing the TXSF6n flag.
CHAPTER 14 SERIAL INTERFACES UART60 AND UART61
Writing enabled
Writing disabled
Transmission is completed.
Transmission is in progress.
User’s Manual U17554EJ4V0UD
Writing to TXB6 Register
Transmission Status
An