xr16c864iq Exar Corporation, xr16c864iq Datasheet - Page 6

• Manufacturer Part Number: xr16c864iq
• Description: Quad Uart With Rx/tx Fifo Counters And 128-byte Fifo
• Manufacturer: Exar Corporation

XR16C864
2.97V TO 5.5V QUAD UART WITH 128-BYTE FIFO
Pin Description
ANCILLARY SIGNALS
CLKSEL
DTRA#
DTRB#
DTRC#
DTRD#
DSRA#
DSRB#
DSRC#
DSRD#
OP1C#
OP1D#
OP2C#
OP2D#
BCLKA
BCLKB
BCLKC
BCLKD
OP1A#
OP1B#
OP2A#
OP2B#
16/68#
XTAL1
XTAL2
CDA#
CDB#
CDC#
CDD#
N
RIA#
RIB#
RIC#
RID#
AME
100-QFP
P
21
60
72
23
58
74
99
32
49
83
98
33
48
84
28
53
78
29
52
79
40
41
30
51
80
36
35
IN
9
7
3
2
1
#
T
YPE
O
O
O
O
O
I
I
I
I
I
UART channels A-D Data-Terminal-Ready (active low) or general purpose output. If
these outputs are not used, leave them unconnected.
UART channels A-D Data-Set-Ready (active low) or general purpose input. This input
should be connected to VCC when not used.
UART channels A-D Carrier-Detect (active low) or general purpose input. This input
should be connected to VCC when not used.
UART channels A-D Ring-Indicator (active low) or general purpose input. This input
should be connected to VCC when not used.
General purpose output or RS-485 direction control signal. RS-485 direction control can
be selected via FCTR bit-3.
outputs are unused, leave them unconnected.
General purpose output. If these outputs are unused, leave them unconnected.
Crystal or external clock input. This input is not 5V tolerant.
Crystal or buffered clock output.
Baud Rate Generator Output. The baud rate generator clock output is internally con-
nected to the RCLK input. This pin provides the 16X clock of the selected data rate from
the baud rate generator.
Intel or Motorola Bus Select (input with internal pull-up).
When 16/68# pin is at logic 1, 16 or Intel Mode, the device will operate in the Intel bus
type of interface.
When 16/68# pin is at logic 0, 68 or Motorola mode, the device will operate in the Motor-
ola bus type of interface.
Baud-Rate-Generator Input Clock Prescaler Select for channels A-D. 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 initialization. See MCR
bit-7 and
Figure 5
in the Baud Rate Generator section.
6
See “Auto RS485 Half-duplex Control” on page 18.
D
ESCRIPTION
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REV. 2.0.1
If these