GreenCoder™ UR5HCFJL
Extremely Low-Power Keyboard
Encoder for Portable Systems
HID & SYSTEM MANAGEMENT PRODUCTS, KEYCODER® FAMILY
DESCRIPTION
The GreenCoder™ UR5HCFJL is a
unique, extremely low-power
keyboard encoder that performs
optimally in both battery-operated
and desktop systems.
The GreenCoder™ scans,
debounces, and encodes an
8 X 16* keyboard matrix, and
provides direct drive for 3 LEDs and
a bi-directional port for
communication with a BIOS-
compatible system as well as an
external port* for a keyboard-type
device. It fully supports all three
PS/2 scan code sets and can
implement up to four keyboard
layers for full 101/102/104
functionality.
The GreenCoder™ employs a
unique Self-Power Management™
method that reduces the power
consumption of the keyboard
sub-system to an unprecedented
minimum, transparently and without
user intervention. In “Active” mode,
the encoder consumes less than 2
mA (Typ @5V). In “Sleep” mode the
encoder consumes less than 2 µA
(Typ @5V). The encoder can even
nap between keystrokes, and
therefore it is rarely active and
rarely consumes significant levels of
power.
A "stand-by" mode (600 µA Typ
@5V) is entered for as long as a
periodic task is active. After a
programmed period of inactivity the
GreenCoder™ gradually dims the
LEDs for further power savings.
The GreenCoder™ is ideal for use
in battery laptop/notebook designs
and Energy Star compliant
keyboards.
Semtech and KeyCoder are registered trademarks
of Semtech Corporation. GreenCoder and Self-
Power management are trademarks of Semtech
Corporation. All other trademarks belong to their
respective companies.
Copyright ©1997-2002 Semtech Corporation
DOC5-FJL-DS-110
PRELIMINARY
FEATURES
• Optimized power-saving operation
with idle consumption of less
than 2 µA
• Programmable LED dimming for
further power savings
• Ready to interface to Fujitsu's
1406, 7211, 7316, 7401, and 7654
keyboards
• 3, 3.3, and 5 Volt operation
APPLICATIONS
• Laptops / notebooks
• Portable equipment
PIN ASSIGNMENTS
R6
NL
VX
NC
DRV
_RESET
VCC
OSCI
OSCO
EKC1
NC
• Wakes-up only to respond to an
external event and for a minimum
period of time (2 mA current
consumption)
• Provides interface for external
keyboard/keypad or other 8042-
compatible device*
• Energy Star compliant
• Medical instruments
• Palmtops / PDAs
6
OPT
KD
KC
EKC/C17
EKD/C16
CL
C0
C1
C2
C3
C4
7
1
40
39
12
PLCC
34
*Note:
The UR5HCFJL-7401 scans an 8 x 18 keyboard matrix, and does
not provide a port for an external keyboard.
1
NC
C5
C6
C7
VSS
NC
C15
C14
C13
C12
C11
www.semtech.com
C4
C5
C6
C7
NC
VSS
C15
C14
C13
C12
NC
17
18
23
29
28
R7
SL
R5
R4
R3
R2
R1
R0
C8
C9
C10
NL
VX
DRV
_RESET
NC
NC
VCC
OSCI
OSCO
EKC1
R7
R6
OPT
KD
KC
EKC/C17
EKD/C16
CL
C0
C1
C2
C3
QFP
SL
R5
R4
R3
R2
R1
R0
C8
C9
C10
C11
ORDERING CODE
Package options
44-pin, Plastic PLCC
44-pin, Plastic QFP
Pitch
1.27 mm
0.8 mm
TA = -40°C to +85°C
UR5HCFJL-xxxx-FN
UR5HCFJL-xxxx-FB
Note:
“xxxx” = “16” for FKB7316 matrix compatibility, “11” for FKB7211, “06” for FKB1406, “7401” for
FKB7401, “7654” for FKB7654
FUNCTIONAL DIAGRAM
NL/CL/SL
3
Data Buffer
Status LEDs
R0-R7
Row Data Inputs
EKC1
Interrupt Control
Column Select
Ouputs
16
Keyboard Encoder
KC
KD
PC
Communication
Channel
8
C0-C15
16-Bit Timer
Mode Control
8042 Emulation
(External Keyboard)
Communication
Channel
EKC
EKD
DRV
Copyright ©1997-2002 Semtech Corporation
DOC5-FJL-DS-110
2
www.semtech.com
FUNCTIONAL DESCRIPTION
The GreenCoder™ consists
functionally of seven major
sections (see Functional Diagram,
previous page). These are the
Keyboard Encoder, a 16-Bit Timer,
the Mode Control Unit, the Data
Buffer, the Interrupt Control, the PC
Communication Channel and the
8042 Emulation Channel. All
sections communicate with each
other and operate concurrently.
KEYBOARD ENCODER
The encoder scans a keyboard
organized as an 8 row by 16
column matrix for a maximum of
128 keys. Smaller-size keyboards
are supported provided that all
unused row lines are pulled to Vcc.
When active, the encoder selects
one of the column output lines
every 512 µs and then reads the
row input data lines (R0-R7). A
key closure is detected as a 0 in
the corresponding position of the
matrix. A complete scan cycle for
the entire keyboard takes
approximately 9.2 ms. Each key
found pressed is debounced for a
period of 20 ms. Once the key is
verified, the corresponding key
code(s) are loaded into the
transmit buffer of the PC keyboard
communication channel.
PIN DEFINITIONS
Mnemonic
VCC
VX
VSS
_RESET
OSCI
OSCO
OPT
DRV
KC
KD
EKC1
PLCC
44
4
22
1
43
42
7
2
9
8
41
QFP
38
43
17
41
37
36
2
42
4
3
35
Type
I
I
I
I
I
O
I
I
I/O
I/O
I
Name and Function
Power supply:
+5V or +3V or +3.3V
Tie to Vcc
Ground
Reset:
apply 0V to provide orderly start-up
Oscillator input
Oscillator output
Used for options selection
Wake-up line:
used for sleep mode
Keyboard clock:
connects to PC
keyboard port data line
Keyboard data:
connects to
PC port data line
External keyboard clock 1:connects
to external keyboard clock line and is used
to generate an interrupt for every clock line
transmission. For UR5HCFJL-7401 only: tie
to Vcc
External keyboard clock:
connects
to external keyboard data line. For
UR5HCFJL-7401 only: column 17 select
output
External keyboard data:
connect to
external keyboard clock line. For
UR5HCFJL-7401 only: column 16 select
output
Column select outputs:
select one
column
Row data inputs
EKC / C17
10
5
I/O
EKD / C16
11
6
I/O
C0-C4
C5-C7
C8-C15
R0-R5
R6
R7
CL
NL
SL
NC
13-17
19-21
31-24
32-37
6
39
12
5
38
3,18
23, 40
8-12
13-15
26-18
27-32
1
34
7
44
33
39, 40
16, 22
I/O
O
O
I
I
I
O
O
O
Caps lock LED
Num lock LED
Scroll lock LED
No connect:
these pins are unused
Note:
An underscore before a pin mnemonic denotes an active low signal.
Scan Code Table Sets
The GreenCoder™ supports all
three scan code table sets. Scan
code table set 3 allows the user to
program individual key attributes
such as Make/Break and
Typematic or Single-Touch Action.
For more information, refer to the
IBM technical reference manuals.
Copyright ©1997-2002 Semtech Corporation
DOC5-FJL-DS-110
3
www.semtech.com
KEYBOARD ENCODER (CONT’D)
N-KEY ROLLOVER
Embedded Numeric Keypad
The GreenCoder™ implements an
embedded numeric keypad. The
Numeric Keypad Function is
invoked by pressing the Num Lock
Key.
N-Key Rollover
In this mode, the code(s) corresponding to each key press are transmitted
to the host system as soon as that key is debounced, independently of the
release of other keys.
If a key is defined to be Typematic, the corresponding make code(s) are
transmitted while the key is held pressed. When a key is released, the
corresponding break code(s) are then transmitted to the host system. If the
released key happens to be the most recently pressed, then Typematic
action is terminated. There is no limitation in the number of keys that can
be held pressed at the same time. However, two or more key closures,
occurring within a time interval less than 5 ms, will set an error flag and will
not be processed. This procedure protects against the effects of accidental
key presses.
GHOST KEYS
Status LED indicators
The controller provides an interface
for three LED shift status indicators.
All three pins are active low to
indicate the status of the host
system (Num Lock, Caps Lock and
Scroll Lock) and are set by the
system. After approximately a one-
minute period of keyboard inactivity,
LEDs are dimmed to conserve
power. They are set to full
brightness again upon a new
keystroke.
“Ghost” Keys
In any scanned contact switch matrix, whenever three keys defining a
rectangle on the switch matrix are held pressed at the same time, a fourth
key positioned on the fourth corner of the rectangle is sensed as being
pressed. This is known as the “ghost” or “phantom” key problem. Although
the problem cannot be totally eliminated without using external hardware,
there are methods to neutralize its
Actual key presses
negative effects for most practical
applications. Keys that are intended to
be used in combinations or are likely to
be pressed at the same time by a fast
typist (i.e., keys located in adjacent
positions on the keyboard) should be
“Ghost”
Key
placed in the same row or column of the
matrix whenever possible. Shift Keys
(Shift, Alt, Ctrl) should not reside in the
same row (or column) with any other
keys. The GreenCoder™ has built-in
Figure 1:
“Ghost” or “Phantom” Key
mechanisms to detect the presence of a
Problem
“ghost” key, thus eliminating the necessity
of external hardware.
Copyright ©1997-2002 Semtech Corporation
DOC5-FJL-DS-110
4
www.semtech.com
8042 EMULATION CHANNEL
The GreenCoder™ fully emulates a
system’s keyboard port*, available
to any PS/2 keyboard-type 8042-
compatible device. The
GreenCoder™ communicates with
the external device using clock
and data lines connected to the
EKC and EKD pins, respectively.
The EKC1 pin also connects to the
clock line, and interrupts the
GreenCoder™ whenever the
external device initiates a
communication session.
When power is first applied, the
GreenCoder™ performs the
standard reset sequence with the
external device. Data and
commands initiated from the
external device are buffered in the
GreenCoder™’s FIFO along with
data from the scanned matrix; all
these are presented to the host as
if from a single keyboard. Once
they are acknowledged,
commands and data from the
system are relayed to the external
device.
SPECIAL HANDLING
Connection of External Device*
The GreenCoder™ detects the presence of an external device. If an
external keyboard or other device was not connected during power-on and
is connected at a later time, the GreenCoder™ proceeds with the normal
reset routine in order to properly initialize the external device. After
communication has been established, the GreenCoder™ continues to
check for the presence of the external device. While the external device is
connected, the GreenCoder™ does not enter the sleep mode. If the
device is disconnected at a later time, the GreenCoder™ becomes aware
of it. If a subsequent connection takes place, the GreenCoder™ re-
initiates a reset sequence. This unique feature allows the user to connect
or disconnect an external device at any time without having to reset the
system.
Shift Status LEDs
Shift Status LEDs (Num Lock, Caps Lock and Scroll Lock) indicate the
status of the system and are controlled by commands sent from the
system. Set/Reset Status Indicator Commands from the system are
executed both by the external keyboard and the scanned matrix.
For example, if the user presses the Caps Lock Key on either keyboard,
the Caps Lock LED is affected on both keyboards. The LED status
indicators are properly set after each new connection of an external
keyboard.
*Note:
The UR5HCFJL-7401 does not provide a port for an external device.
Copyright ©1997-2002 Semtech Corporation
DOC5-FJL-DS-110
5
www.semtech.com
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