UR7HCTS2-S840-FG Semtech Corporation, UR7HCTS2-S840-FG Datasheet - Page 7

• Manufacturer Part Number: UR7HCTS2-S840-FG
• Description: High-Performance/ Low Power Touch Screen Controller/Digitizer
• Manufacturer: Semtech Corporation

The ScreenCoder
supports either Serial Peripheral
Interface (SPI) or Asynchronous
Serial Interface (Serial)
communication based on the
power-up setting of the ISEL/SCLK
pin. To select the Asynchronous
Serial Interface, connect
ISCL/SCLK to VSS. For SPI
interface, SCLK must idle high.
Data Packet Format for
ScreenCoder
The ScreenCoder
two different types of mouse
packages. One type is for absolute
position data from the touch screen
sensor and one is for relative data
from the external PS/2 device.
For both the Relative and Absolute
mode package format, each
packet contains 4 bytes. The 7th
bit of each byte is used for
synchronization. The 7th bit for the
first byte is 1 and for the other
bytes is 0. The resolution for
absolute position is 10 bits
(approximately 1000 points in X
and Y directions.) The relative
mouse data format supports
operations with WheelMouse and
5-button mice.
Identification and Revision for
ScreenCoder
The UR7HCTS2-S840 offers a
special identification and revision
package. This package uses the
absolute mode format, but will not
appear in the normal absolute
mode. For normal absolute mode,
the first byte will be 80 Hex or 9F
Hex. This special 4-byte package
is identified by the first byte, 81
Hex. This data package is sent
upon power-up.
Copyright Semtech 2000-2001
DOC7-TS2-S840-DS-102
SERIAL PERIPHERAL INTERFACE (SPI) AND ASYNCHRONOUS SERIAL INTERFACE (SERIAL)
TM
TM
SPI/Serial
SPI/Serial
TM
TM
SPI/Serial has
SPI/Serial
Byte # 7
1
2
3
4
(See Note 4 below)
Note 4:
C3-C0: Class ID
F4-F0: Family ID
P2-P0: Sub Product Family
V8-V0: Revision
Byte # 7
1
2
3
4
Byte # 7
1
2
3
4
Note 2: The bits that are marked with X* are reserved for future use. Now the value given is
zero.
Note 3: The X / Y data from external mouse is 9 bits. In our report, we truncate it to 8 bits.
The reduction is based on the fact that X / Y increments are seldom beyond the range of
+127/-128. For mouse data that exceeds this range, the ScreenCoder
+127/-128.V8-V0: Revision
7
ABSOLUTE MODE PACKAGE FORMAT
RELATIVE MODE PACKAGE FORMAT
IDENTIFICATION AND REVISION REPORT PACKAGE FORMAT
1
0
0
0
1
0
0
0
1
0
0
0
6
0
Mouse
X6
Y6
X*
6
0
F4
P2
V6
6
0
Mouse
Y9
X6
Y6
5
0
V8
P1
V5
Hex 7
Hex A
Hex 1
Hex 40
5
0
Absolute 1 penup 1 penup 1 penup 1 penup 1 penup
Y8
X5
Y5
5
1
Relative
X5
Y5
B5
Bit Number
4
0
V7
P0
V4
UR7HC
TS2
S840
(Current Revision here)
Bit Number
4
0
Y7
X4
Y4
Bit Number
4
Ysign
X4
Y4
B4
Hex 40
3
0
C3
F3
V3
3
0
X*
X3
Y3
3
Xsign
X3
Y3
Z3
(Current Revision here)
www.semtech.com
2
M
X2
Y2
Z2
2
0
C2
F2
V2
2
0
X9
X2
Y2
TM
1
R
X1
Y1
Z1
1
0
C1
F1
V1
1
0
X8
X1
Y1
SPI/Serial will give
0
L
X0
Y0
Z0
0
1
C0
F0
V0
0
0
X7
X0
Y0