xr16l2751im Exar Corporation, xr16l2751im Datasheet - Page 8

• Manufacturer Part Number: xr16l2751im
• Description: 2.25v To 5.5v Duart With 64-byte Fifo And Powersave
• Manufacturer: Exar Corporation

XR16L2751
2.25V TO 5.5V DUART WITH 64-BYTE FIFO AND POWERSAVE
The CPU interface is 8 data bits wide with 3 address lines and control signals to execute data bus read and
write transactions. The 2751 data interface supports the Intel compatible types of CPUs and it is compatible to
the industry standard 16C550 UART. No clock (oscillator nor external clock) is required to operate a data bus
transaction. Each bus cycle is asynchronous using CSA/B#, IOR# and IOW# or CS#, R/W# and A3 inputs.
Both UART channels share the same data bus for host operations. A typical data bus interconnection for Intel
and Motorola mode is shown in
F
2.0 FUNCTIONAL DESCRIPTIONS
2.1
IGURE
3. XR16L2751 T
CPU Interface
UART_RESET#
UART_RESET
UART_CSA#
UART_CSB#
UART_IRQ#
UART_CS#
UART_INTA
UART_INTB
RXRDYA#
RXRDYB#
TXRDYA#
TXRDYB#
TXRDYA#
RXRDYA#
TXRDYB#
RXRDYB#
R/W#
IOW #
IOR#
A0
A1
A2
D0
D1
D2
D3
D4
D5
D6
D7
A3
A0
A1
A2
D0
D1
D2
D3
D4
D5
D6
D7
YPICAL
Figure
I
NTEL
/M
Motorola Data Bus Interconnections
3.
OTOROLA
Intel Data Bus Interconnections
VCC
(no connect)
VCC
D
ATA
8
B
CSB#
IOW#
CSA#
RESET#
IOR#
INTA
INTB
IOW #
CSA#
CSB#
TXRDYA#
RXRDYA#
TXRDYB#
RXRDYB#
IOR#
D0
D1
D2
D3
D4
D5
D6
D7
US
INTA
INTB
TXRDYA#
RXRDYA#
TXRDYB#
RXRDYB#
RESET
A0
A1
A2
D0
D1
D2
D3
D4
D5
D6
D7
A0
A1
A2
I
NTERCONNECTIONS
Channel A
Channel B
Channel A
Channel B
UART
UART
UART
UART
DSRA#
DTRA#
RTSA#
CTSA#
DTRB#
DSRB#
RTSB#
CTSB#
DTRA#
DSRA#
OP2A#
OP2B#
RTSA#
CTSA#
DTRB#
DSRB#
OP2A#
RTSB#
CTSB#
CDA#
OP2B#
CDB#
CDA#
GND
CDB#
RIA#
GND
RIB#
VCC
TXA
RXA
RIA#
TXB
RXB
VCC
RIB#
TXA
RXA
RXB
TXB
2.25 to 5.5 Volt VCC
VCC
(no connect)
(no connect)
(no connect)
(no connect)
RS-232 Serial Interface
RS-232 Serial Interface
Serial Interface of
Serial Interface of
RS-232, RS-485
RS-232, RS-485
2750_int
xr
REV. 1.2.2