Texas Instruments TMS320C3x - Manual (Page 399)

Serial Ports
12-20
Table 12–2. Serial-Port Global-Control Register Bits Summary (Continued)
Abbreviation Description Name
Reset
Value
CLKRP 0 CLKR polarity If CLKRP = 0, CLKR is active (high).
If CLKRP = 1, CLKR is active (low).
DXP 0 DX polarity If DXP = 0, DX is active (high).
If DXP = 1, DX is active (low).
DRP 0 DR polarity If DRP = 0, DR is active (high).
If DRP = 1, DR is active (low).
FSXP 0 FSX polarity If FSXP = 0, FSX is active (high).
If FSXP = 1, FSX is active (low).
FSRP 0 FSR polarity If FSRP = 0, FSR is active (high).
If FSRP = 1, FSR is active (low).
XLEN 00 Transmit word length These two bits define the word length of serial data trans-
mitted. All data is assumed to be right justified in the transmit
buffer when fewer than 32 bits are specified.
0 0 — 8 bits 1 0 — 24 bits
0 1 — 16 bits 1 1 — 32 bits
RLEN 00 Receive word length These two bits define the word length of serial data received.
All data is right justified in the receive buffer.
0 0 — 8 bits 1 0 — 24 bits
0 1 — 16 bits 1 1 — 32 bits
XTINT 0 Transmit timer
interrupt enable If XTINT = 0, the transmit timer interrupt is disabled.
If XTINT = 1, the transmit timer interrupt is enabled.
XINT 0 Transmit interrupt
enable If XINT = 0, the transmit interrupt is disabled.
If XINT = 1, the transmit interrupt is enabled.
Note: The CPU receive flag XINT and the serial-port-to-DMA
interrupt (EXINT0 in the IE register) is the OR of the enabled
transmit timer interrupt and the enabled transmit interrupt.
RTINT 0 Receive timer
interrupt enable If RTINT = 0, the receive timer interrupt is disabled.
If RTINT = 1, the receive timer interrupt is enabled.