TMP88PH41NG Datasheet, PDF (148/194 Pages) Toshiba Semiconductor – 8 Bit Microcontroller

13. Asynchronous Serial interface (UART)
13.2 Control
TMP88PH41NG
13.2 Control
UART is controlled by the UART Control Registers (UARTCRA, UARTCRB). The operating status can be mon-
itored using the UART status register (UARTSR).
UART Control Register1
UARTCRA
7
6
5
4
3
(01F91H)
TXE
RXE STBT EVEN
PE
2
1
0
BRG
(Initial value: 0000 0000)
TXE Transfer operation
RXE Receive operation
STBT Transmit stop bit length
EVEN Even-numbered parity
PE
Parity addition
BRG Transmit clock select
0: Disable
1: Enable
0: Disable
1: Enable
0: 1 bit
1: 2 bits
0: Odd-numbered parity
1: Even-numbered parity
0: No parity
1: Parity
000: fc/13 [Hz]
001: fc/26
010: fc/52
011: fc/104
100: fc/208
101: fc/416
110: Input INTTC4
111: fc/96
Write
only
Note 1: When operations are disabled by setting UARTCRA<TXE and RXE> bits to “0”, the setting becomes valid when data
transmit or receive complete. When the transmit data is stored in the transmit data buffer, the data are not transmitted.
Even if data transmit is enabled, until new data are written to the transmit data buffer, the current data are not transmitted.
Note 2: The transmit clock and the parity are common to transmit and receive.
Note 3: UARTCRA<RXE> and UARTCRA<TXE> should be set to “0” before UARTCRA<BRG> is changed.
Note 4: In case fc = 20MHz, the timer counter 4 (TC4) is available as a baud rate generator.
UART Control Register2
UARTCRB
7
6
5
4
3
2
1
0
(01F92H)
RXDNC
STOPBR (Initial value: **** *000)
Selection of RXD input noise
RXDNC
rejectio time
STOPBR Receive stop bit length
00: No noise rejection (Hysteresis input)
01: Rejects pulses shorter than 31/fc [s] as noise
10: Rejects pulses shorter than 63/fc [s] as noise
11: Rejects pulses shorter than 127/fc [s] as noise
0: 1 bit
1: 2 bits
Write
only
Note: When UARTCRB<RXDNC> = “01”, pulses longer than 96/fc [s] are always regarded as signals; when UART-
CRB<RXDNC> = “10”, longer than 192/fc [s]; and when UARTCRB<RXDNC> = “11”, longer than 384/fc [s].
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