OXuPCI952
OXFORD SEMICONDUCTOR, INC.
Serial Port Pins – Mode 0 and Mode 1
Pin
Dir1
Name
Description
65, 60
These two pins are present in all modes but they can serve
one of three functions, as follows:
O(h) DTR[1:0]#
O(h) 485_En[1:0]
Active-low modem data-terminal-ready output. If automated
DTR# flow control is enabled, the DTR# pin is asserted and
deasserted if the receiver FIFO reaches or falls below the
programmed thresholds, respectively.
In RS485 half-duplex mode, the DTR# pin may be
programmed to reflect the state of the transmitter empty bit
to automatically control the direction of the RS485
transceiver buffer (see register ACR[4:3]).
O(h) Tx_Clk_Out[1:0] Transmitter 1x clock (baud rate generator output). For
isochronous applications, the 1x (or Nx) transmitter clock
may be asserted on the DTR# pins (see register CKS[5:4]).
64, 61
67, 59
O(h) RTS[1:0]#
Active-low modem request-to-send output. If automated
RTS# flow control is enabled, the RTS# pin is deasserted
and reasserted whenever the receiver FIFO reaches or falls
below the programmed thresholds, respectively.
Active-low modem clear-to-send input. If automated CTS#
flow control is enabled, upon deassertion of the CTS# pin,
the transmitter will complete the current character and enter
the idle mode until the CTS# pin is reasserted. Note: flow
control characters are transmitted regardless of the state of
the CTS# pin.
I(h)
CTS[1:0]#
66, 58
These two pins are present in all modes but they can serve
one of two functions, as follows:
I(h)
DSR[1:0]#
Active-low modem data-set-ready input. If automated DSR#
flow control is enabled, upon deassertion of the DSR# pin,
the transmitter will complete the current character and enter
the idle mode until the DSR# pin is reasserted. Note: flow
control characters are transmitted regardless of the state of
the DSR# pin.
I(h)
I(h)
I(h)
Rx_Clk_In[1:0]
RI[1:0]#
External receiver clock for isochronous applications. The
Rx_Clk_In is selected when CKS[1:0] = ‘01’.
Active-low modem Ring-Indicator input.
70, 56
Tx_Clk_In[1:0]
External transmitter clock. This clock can be used by the
transmitter (and indirectly by the receiver) when CKS[6]=’1’.
DS-0059 Sep 07
Page 11
OXFORD [ OXFORD SEMICONDUCTOR ]
