tmp88f846ug TOSHIBA Semiconductor CORPORATION, tmp88f846ug Datasheet - Page 159

• Manufacturer Part Number: tmp88f846ug
• Description: 8 Bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

15. Asynchronous Serial interface (UART)
15.1 Configuration
TXD and RXD pin. TXD and RXD pin are also used as the general port. For TXD pin, the corresponding general
port should be set output mode (Set its output control register to "1" after its output port latch to "1"). For RXD pin,
should be set input mode.
tion frequency. Moreover, the oscillation frequency changes and it is impossible to communicate by the temperature
change etc. Therefore, we recommend you to adjust the transmission rate by the communication protocol as follows.
The TMP88F846UG has a asynchronous serial interface (UART) . It can connect the peripheral circuits through
This UART and SIO can not use simultaneously because their input/output ports are common.
When using UART of TMP88F846UG, it might be impossible to communicate because of the error of the oscilla-
[For Example]
fc/13
fc/26
fc/52
fc/104
fc/208
fc/416
INTTC4
fc/96
1. Fixed data (ex: 05AH) is transmitted at head byte of transmission data or constant intervals from the host
2. The host side keeps transmitting fixed data until receiving the ACK from remote side. The usual communi-
3. Remote side adjusts a transfer rate finely until receiving fixed data. When receiving fixed data, an ACK is
INTRXD
INTTXD
side whose oscillation is stable.
cation is restarted after ACK reception.
transmitted to host and communication is usually restarted.
UART control register 1
A
B
C
D
E
F
G
H
Figure 15-1 UART (Asynchronous Serial Interface)
S
UARTCRA
3
Y
2
Baud rate generator
Counter
Transmit/receive clock
Transmit data buffer
Shift register
TDBUF
Page 149
2
UART status register UART control register 2
2
UARTSR
4
Receive data buffer
Parity bit
Stop bit
Noise rejection
Shift register
UARTCRB
M
P
X
circuit
RDBUF
Y
S
2
A
B
C
fc/2
fc/2
fc/2
MPX: Multiplexer
6
7
8
TMP88F846UG
RXD
TXD