XR17V254_08 Datasheet, PDF (21/70 Pages) Exar Corporation – 66MHZ PCI BUS QUAD UART WITH POWER MANAGEMENT SUPPORT

REV. 1.0.1
XR17V254
66MHZ PCI BUS QUAD UART WITH POWER MANAGEMENT SUPPORT
FIGURE 8. INTERRUPT OUTPUT (ACTIVE LOW) IN ONE-SHOT AND RE-TRIGGERABLE MODES
Timer Started
Timer Timed
Out
TIMERCNTL
read
One-shot Mode
Timer Timed TIMERCNTL Timer Timed
Out
read
Out
Re-triggerable
Mode
1.6.3 8XMODE [7:0] (default 0x00)
Each bit selects 8X or 16X sampling rate for that UART channel, bit [0] is channel 0. Logic 0 (default) selects
normal 16X sampling with logic one selects 8X sampling rate. Transmit and receive data rates will double by
selecting 8X.
8XMODE Register
Individual UART Channel 8X Clock Mode Enable
Bit-7 Bit-6 Bit-5 Bit-4 Bit-3 Bit-2 Bit-1 Bit-0
Rsvd Rsvd Rsvd Rsvd Ch-3 Ch-2 Ch-1 Ch-0
1.6.4 REGA [15:8] (default 0x00) Reserved
1.6.5 RESET [23:16] (default 0x00)
The 8-bit Reset register [RESET] provides the software with the ability to reset the UART(s) when there is a
need. Each bit is self-resetting after it is written a logic 1 to perform a reset to that channel. All registers in that
channel will be reset to the default condition, see Table 21 for details. bit [0] =1 resets UART channel 0 with bit
[7]=1 resets channel 7.
RESET Register
Individual UART Channel Reset Enable
Bit-7 Bit-6 Bit-5 Bit-4 Bit-3 Bit-2 Bit-1 Bit-0
Rsvd Rsvd Rsvd Rsvd Ch-3 Ch-2 Ch-1 Ch-0
21