xr16m2751 Exar Corporation, xr16m2751 Datasheet - Page 6

• Manufacturer Part Number: xr16m2751
• Description: High Performance Duart With 64-byte Fifo And Powersave
• Manufacturer: Exar Corporation

XR16M2751
1.62V TO 3.63V HIGH PERFORMANCE DUART WITH 64-BYTE FIFO
Pin Description
Pin type: I=Input, O=Output, I/O= Input/output, OD=Output Open Drain.
HDCNTL#
(RESET#)
CLKSEL
RESET
16/68#
N
VCC
GND
AME
48-TQFP
P
24
25
37
36
42
17
IN
#
T
Pwr
Pwr
YPE
I
I
I
I
Intel or Motorola Bus Select.
When 16/68# pin is HIGH, 16 or Intel Mode, the device will operate in the Intel bus
type of interface.
When 16/68# pin is LOW, 68 or Motorola mode, the device will operate in the Motor-
ola bus type of interface.
Baud-Rate-Generator Input Clock Prescaler Select for channel A and B. This input is
only sampled during power up or a reset. Connect to VCC for divide by 1 and GND
for divide by 4. MCR[7] can override the state of this pin following a reset or initializa-
tion. See MCR bit-7 and
Auto RS-485 half-duplex direction output enable for channel A and B (active low).
Connect this pin to VCC for normal RTS# A/B function and to GND for auto RS-485
half-duplex direction output via the RTS# A/B pins. RTS# output goes low for transmit
and high for receive (polarity inversion is available via EMSR[3]). FCTR[3] in channel
A and B have control only if this input is disabled or at VCC.
When 16/68# pin is HIGH for Intel bus interface, this input becomes RESET (active
high). When 16/68# pin is LOW for Motorola bus interface, this input becomes
RESET# (active low).
A 40 ns minimum active pulse on this pin will reset the internal registers and all out-
puts of channel A and B. The UART transmitter output will be held HIGH, the receiver
input will be ignored and outputs are reset during reset period (see Table 17).
1.62V to 3.63V power supply.
Power supply common, ground.
6
Figure 5
in the Baud Rate Generator section.
D
ESCRIPTION
REV. 1.0.0