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Field
Name
R/W
Description
otherwise, the data cannot be transmitted; if CTS signal is pulled to
high during data transmission, the data transmission will be stopped
after the data transmission is completed; if write operation is performed
for the data register when CTS is high, the data will not be transmitted
until CTS is valid.
This bit can be set only when USART is not enabled.
10
CTSIEN
R/W
CTS Interrupt Enable
0: Disable
1: Generate an interrupt when CTSFLG is set
11
SAMCFG
R/W
Sample Method Configure
0:
Sampling for three times
1:
Single sample; flag of noise detection disabled
This bit can be set only when USART is not enabled.
12
OVRDEDIS
R/W
Overrun Detection Disable
0: Enable. When RXBNEFLG bit is set and
new data is received,
OVREFLG bit will be set.
1: Disable
.
When new data are received, if RXBNEFLG is still set but
OVREFLG is not set, the data not read will be covered by new data.
This bit can be set only when USART is not enabled.
13
DDISRXEEN
R/W
DMA Disable on Receive Error Enable
0:
DMA not disabled.
The corresponding error flag bit will be set, but in
order to avoid data from overrunning and being covered, RXBNEFLG
will not be set.
In smart card mode, as a result, no DMA request will be
issued, so wrong data will not be transmitted, but the next correct data
will be transmitted.
1: DMA disabled
.
If RXBNEFLG is set, the corresponding error flag bit
will also be set.
DMA request will not be masked only when the
corresponding error flag bit is cleared.
Therefore, it is required to first
disable DMA request or first clear RXBNEFLG flag and then clear the
error flag.
This bit can be set only when USART is not enabled.
14
DEN
R/W
Driver Enable
Users are allowed to activate the control terminal of external
transceiver through DE signal.
0: DE function disabled
1: DE function enabled, DE signal output on RTS pin
This bit can be set only when USART is not enabled.
15
DPCFG
R/W
Driver Polarity Configure
0: DE signal high level is valid
1: DE signal low level is valid
This bit can be set only when USART is not enabled.
31:16
Reserved
Baud rate register (USART_BR)
This register can be set only when USART is not enabled. This bit may be reset
by hardware during automatic baud rate detection.
Offset address: 0x0C
Reset value: 0x0000
Field
Name
R/W
Description
3:0
FBR
R/W
Fraction of USART Baud Rate Divider factor
The decimal part of USART baud rate division factor is determined by these
four bits.