PIN DEFINITIONS
Pin Numbers
Mnemonic LQFP Type Name and Function
Power Supply
VDD 8 PWR Positive Supply Voltage: +3V-+5V
VREF 5 AI Positive Analog Ref Voltage
VSS 11 PWR Ground: analog signal
VSS2 7 PWR Ground: negative supply voltage
_RESET 6 I Hardware Reset Pin:
at Low-level, this pin holds the
UR6HCPS2-SP40 in a reset state.
Oscillator Pins
OSCIN 9 I Oscillator input: connect ceramic
resonator with built-in load capacitors
or CMOS clock from external oscillator
4 MHz operating frequency
_OSCOUT 10 O Oscillator Output: connect ceramic
resonator with built-in load capacitors
or keep open if external oscillator
is used
PS/2 Ports
E0CLK 18 I/nD PS/2 Clock: for External Device 0
E0DATA 19 I/nD PS/2 Data: for Exter nal Device 0
E1CLK 20 I/nD PS/2 Clock: for External Device 1
E1DATA 21 I/nD PS/2 Data: for Exter nal Device 1
E2CLK 22 I/nD PS/2 Clock: for External Device 2
E2DATA 23 I/nD PS/2 Data: for Exter nal Device 2
E3CLK 24 I/nD PS/2 Clock: for External Device 3
E3DATA 25 I/nD PS/2 Data: for Exter nal Device 3
System Status
Monitoring
_PWR_OFF 30 I±Int Power Off Signal: capable of
Interrupt on both Positive and Negative
edges
X_PWR 4 AI External PS/2 Device Power
Detector
Communication
Interface
_SS/_RTS 17 I_Int Ready_To_Send: Active-Low
signal Input.Low-level indicates that
the Host System is ready to send
data from UR6HCPS2-SP40.
_ATN/_CTS 31 O Attention (SPI Mode) or
Clear_To_Send (Asynchronous
Serial Mode ): Active-Low signal
Output. Low-level indicates that the
UR6HCPS2-SP40 has data to send to
the Host System
TXD 27 O Transmit Data (Asynchronous
Serial Mode): Idle = "High" = 1
RXD 26 I Receive Data (Asynchronous
Serial Mode): Reserved future use
SDATA 29 Master-In-Slave-Out (SPI Mode):
keep open for ASI mode or tie to Gnd
SCLK 28 I Serial Clock (SPI Mode): in SPI
Mode, use the following Clock
sequence:Idle-high/ Negative-Edge
(Shift Data) \ Positive-Edge (Latch
Data), Idle-High. Keep open or tie to
Gnd for ASI mode
FUNCTIONAL DESCRIPTION
Copyright Semtech, 2002-2001
DOC6-PS2-SP40-DS-102
www.semtech.com
3
The PS2AdaptTMconsists
functionally of three major sections.
These are the Dual Mode Serial
Communications Interface, the
Power Management Unit, and the
HID Manager. All sections
communicate with each other and
operate concurrently.
HID MANAGER
OPERATIONS BELOW 5 V
The UR6HCPS2-SP40 Human Input
Device (HID) Manager is
responsible for the configuration
and handling of HID devices that
are attached to the controller
through the four external PS/2 ports.
The HID Manager has the following
responsibilities:
1. Initialize PS/2 keyboards and
mice
2. Mix the information from external
PS/2 devices
3. Formatting and relaying reports of
the HID devices to the Host.
The standard PS/2 devices are
specified for supply voltage of 5V.
Operations of the UR6PS2-SP40 at
a lower voltage (3V) are only
possible if the HID devices
connected to ALL external PS/2
ports are capable of 3V operations.