XR17D158 Exar Corporation, XR17D158 Datasheet - Page 3

• Manufacturer Part Number: XR17D158
• Description: Eight-channel Pci-bus Uart
• Manufacturer: Exar Corporation

XR17D158
UNIVERSAL (3.3V AND 5V) PCI BUS OCTAL UART
REV. P1.0.0
PIN DESCRIPTIONS
Pin Description
PCI LOCAL BUS INTERFACE
MODEM OR SERIAL I/O INTERFACE
AD31-AD25,
AD23-AD16,
AD15-AD8,
DEVSEL#
FRAME#
AD7-AD0
C/BE0#-
C/BE3#
STOP#
PERR#
SERR#
TRDY#
CTS0#
DTR0#
RTS0#
IRDY#
IDSEL
AD24,
INTA#
RST#
N
CLK
PAR
RX0
TX0
AME
36,25,14,2
138-144,
26-33,
37-44
P
6-13,
134
135
133
125
132
127
131
126
15
16
17
21
18
24
22
23
IN
1,
3
#
T
OD
OD
YPE
IO
IO
O
O
O
O
O
O
O
I
I
I
I
I
I
I
I
Bus reset input (active low). It resets the PCI local bus configuration space
registers, device configuration registers and UART channel registers to the
default condition.
PCI Bus clock input. If VCC = 5V, the maximum PCI clock frequency is
33MHz. If VCC = 3.3V, the maximum PCI clock frequency is 22MHz.
Address data lines [31:0] (bidirectional).
Bus transaction cycle frame (active low). It indicates the beginning and dura-
tion of an access.
Bus Command/Byte Enable [3:0] (active low). This line is multiplexed for bus
Command during the address phase and Byte Enables during the data
phase.
Initiator Ready (active low). During a write, it indicates that valid data is
present on data bus. During a read, it indicates the master is ready to accept
data.
Target Ready (active low).
Target request to stop current transaction (active low).
Initialization device select (active high).
Device select to the XR17D158 (active low).
Device interrupt from XR17D158 (open drain, active low).
Parity is even across AD[31:0] and C/BE[3:0]# (bidirectional, active high).
Data Parity error indicator, except for Special Cycle transactions (active low).
Optional in bus target application.
System error indicator, Address parity or Data parity during Special Cycle
transactions (open drain, active low). Optional in bus target application.
UART channel 0 Transmit Data or infrared transmit data.
idles at logic 1 condition. The infrared pulses can be inverted internally prior
the decoder by FCTR[4].
UART channel 0 Request to Send or general purpose output (active low).
UART channel 0 Clear to Send or general purpose input (active low).
UART channel 0 Data Terminal Ready or general purpose output (active low).
UART channel 0 Receive Data or infrared receive data. Normal RXD input
3
D
ESCRIPTION
PRELIMINARY
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