XR19L220_07 Datasheet, PDF (6/43 Pages) Exar Corporation – SINGLE CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER

XR19L220
SINGLE CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER
REV. 1.0.1
2.0 FUNCTIONAL DESCRIPTIONS
2.1 CPU Interface
The CPU interface is 8 data bits wide with 3 address lines and control signals to execute data bus read and
write transactions. The L220 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 CS#, IOR# and IOW# or R/W# inputs. A typical data bus
interconnection for Intel and Motorola mode is shown in Figure 3.
FIGURE 3. XR19L220 TYPICAL INTEL/MOTOROLA DATA BUS INTERCONNECTIONS
D0
D1
D2
D3
D4
D5
D6
D7
A0
A1
A2
IOR#
IOW#
UART_CS#
UART_INT
UART_RESET
Power-Save
D0
D1
D2
D3
D4
D5
D6
D7
A0
A1
A2
VCC
R/W#
4.7K
UART_IRQ#
UART_CS#
UART_RESET#
Power-Save
D0
D1
D2
D3
D4
D5
D6
D7
A0
A1
A2
IOR#
IOW#
CS#
INT
RESET
PwrSave
VCC
16/68#
TX
RX
DTR
RTS
CTS
DSR
CD
RI
GND
VCC
Full RS-232
Interface
Intel Data Bus Interconnections
VCC
D0
D1
D2
D3
D4
D5
D6
D7
A0
A1
A2
IOR#
IOW#
CS#
INT
RESET
PwrSave
VCC
TX
RX
DTR
RTS
CTS
DSR
CD
RI
16/68#
GND
VCC
Full RS-232
Interface
Motorola Data Bus Interconnections
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