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C2K User’s Guide
Resources
USART Transmit Buffer Register
The USART Transmit Buffer Register holds the data to be transmitted. Its contents are automati-
cally transferred to the outgoing shift register. In FIFO mode, writes to this register are pushed to
the bottom of the memory buffer.
USART Interrupt Enable Register
The USART Interrupt Enable Register provides a mechanism to enable individual causes to gen-
erate an external USART interrupt.
USART Interrupt Identification Register
The USART Interrupt Identification Register provides the status and source of the pending
USART interrupt with the highest priority.
Address offset:
USAR0x0
DLAB:
0
Access:
Write-only
Bits
Field
Default
Description
7 - 0
TXDATA
-
Transmit buffer data
Address offset:
USAR0x1
Access:
Read/write
Bit(s)
Field
Default
Description
7 - 4
Not used
-
Not used
3
Modem
0
Modem Status Interrupt Enable—enables the modem status interrupt.
0 = block (mask) interrupt cause
1 = enable interrupt cause
2
Line
0
Received Line Status Interrupt Enable—enables an interrupt indicating
the received line is available.
0 = block (mask) interrupt cause
1 = enable interrupt cause
1
TX
0
Transmit Holding Register Interrupt Enable—enables an interrupt indi-
cating the Transmit Holding Register is empty.
0 = block (mask) interrupt cause
1 = enable interrupt cause
0
RX
0
Receive Data Interrupt Enable—enables an interrupt indicating receive
data is available.
0 = block (mask) interrupt cause
1 = enable interrupt cause
Address offset:
USAR0x2
Access:
Read-only
Bit(s)
Field
Default
Description
7 - 6
FIFO
0b00
FIFO Buffer status—indicates the status of the FIFO buffer.
0b11 = FIFO mode is enabled
5 - 4
Not used
-
Not used
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