
XR17V358
9
REV. 1.0.6
HIGH PERFORMANCE OCTAL PCI EXPRESS UART
EEPROM SIGNALS
EECK
P13
I/O
Serial clock output uses the internal 125 MHz clock divided by 256 (488 KHz)
following power-up or reset to read an external EEPROM. This pin may also
be manually clocked using the Configuration Register REGB.
EECS
R14
I/O
Active high chip select output to an external EEPROM with internal weak pull-
down resistor. Connect an external 4.7K ohm pull-up resistor to this pin to
enable reading of an external EEPROM. This pin may also be manually
enabled using the Configuration Register REGB.
EEDI
P14
O
Write data to EEPROM device. It is manually accessible thru the
Configuration Register REGB.
EEDO
M12
I
Read data from EEPROM device with internal pull-down resistor. It is
manually accessible thru the Configuration Register REGB.
JTAG SIGNALS
TRST#
N4
I
JTAG Test Reset. This signal is active LOW with internal pull-up resistor.
TCK
P3
I
JTAG Test Clock
TMS
M5
I
JTAG Test Mode Select with internal pull-up resistor
TDI
R3
I
JTAG Data Input with internal pull-up resistor
TDO
P4
O
JTAG Data Output
BUCK REGULATOR SIGNALS
ENABLE
C14
I
Logic ’1’ enables, logic ’0’ disables buck regulator output.
LX
LX
A13
A14
O
O
Output of internal buck regulator. Use 4.7 uH inductor and connect to FB pin
as shown in
FB
C11
I
Buck regulator feedback. Decouple with 47uF capacitor and connect to LX
pins through 4.7 uH inductor as shown in
PWRGD
D13
O
Asserted when the 1.2V internal buck voltage is powered up and within
regulation.
ANCILLARY SIGNALS
RESET#
R2
I
System reset (active low). In normal operation, this signal should be HIGH.
TMRCK
A10
I
16-bit timer/counter external clock input.
EN485#
C10
I
Auto RS-485 mode enable (active low). This pin is sampled during power up,
following a hardware reset (RST#) or soft reset (register RESET). It can be
used to start up all 8 UARTs in the Auto RS-485 Half-Duplex Direction control
mode. The sampled logic state is transferred to FCTR bit-5 in the UART
channel.
ENIR#
B10
I
Infrared mode enable (active low). This pin is sampled during power up,
following a hardware reset (RST#) or soft-reset (register RESET). It can be
used to start up all 8 UARTs in the infrared mode. The sampled logic state is
transferred to MCR bit-6 in the UART.
PIN DESCRIPTIONS
N
AME
P
IN
#
T
YPE
D
ESCRIPTION