UART
S3C4510B
UART STATUS REGISTER
Table 10-6. UCON0 and UCON1 Registers
Registers
USTAT0
Offset Address
R/W
R
Description
UART0 status register
UART1 status register
Reset Value
0xC0
0xD008
0xE008
USTAT1
R
0xC0
Table 10-7. UART Status Register Description
Bit Name Reset Value
Bit Number
[0]
Overrun error
USTAT[0] is automatically set to "1" whenever an overrun error
occurs during a serial data receive operation. The overrun error
indicates that the new received data has overwritten old received
data before the old data could be read.
If the receive status interrupt enable bit, UCON[2] is "1", a receive
status interrupt is generated if an overrun error occurs.
This bit is automatically cleared to "0" whenever the UART status
register (USTAT) is read.
[1]
[2]
Parity error
Frame error
USTAT[1] is automatically set to "1" whenever a parity error occurs
during a serial data receive operation. If the receive status interrupt
enable bit, UCON[2], is "1", a receive status interrupt is generated
if a parity error occurs.
This bit is automatically cleared to "0" whenever the UART status
register (USTAT) is read.
USTAT[2] is automatically set to "1" whenever a frame error occurs
during a serial data receive operation. A frame error occurs when a
zero is detected instead of the Stop bit(s).
If the receive status interrupt enable bit, UCON[2] is "1", a receive
status interrupt is generated if a frame error occurs.
The frame error bit is automatically cleared to "0" whenever the
UART status register (USTAT) is read.
[3]
[4]
Break interrupt
USTAT[3] is automatically set to "1" to indicate that a break signal
has been received.
If the receive status interrupt enable bit, UCON[2], is "1", a receive
status interrupt is generated if a break occurs.
The break interrupt bit is automatically cleared to "0" when you
read the UART status register.
Data terminal ready
(DTR)
The USTAT[4] bit indicates the current signal level at the data
terminal ready (DTR) pins (nUADTR). When this bit is "1", the level
at the DTR pin (nUADTR) is Low. When it is "0", the DTR pin is
High level.
10-8
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