Philips 32PF9968/10 Service Manual page 35

Circuit Descriptions, Abbreviation List, and IC Data Sheets
S D A
S da1
S C L
S c l1
S E L1
t bd
S E L2
t bd
AR M
Tx D
Tx d0
R x D
R x d0
Figure 7-8 ARM controller interface
Data transfer between ARM processor and LED drivers is
executed by a Serial Peripheral Interface (SPI) bus interface.
The SPI bus is a synchronous serial data link standard that
operates in full duplex mode.
Am b ilig h t m o d u le 1
L E D
D R IV E R
1
A R M
The ARM controller communicates with the LED drivers (on
each AL module) via an SPI bus. For debugging purposes, the
working principle is given below:
• Data from the ARM controller is linked through the drivers,
which are connected in cascade
• SPI CLK, SPI LATCH, PROG, BLANK and PWM CLOCK
are going directly from the controller to each driver
• SPI DATA RETURN is linked from the last driver to the
controller: controller decides which driver returns data.
7.8.3 Temperature Control
Refer to Figure 7-10 for signal interfacing between the ARM
controller and the temperature sensor on the AL boards.
SPI C LO C K
S c k
SPI LATC H
P 0. 7
SPI LATC H 2
(only on dc/dc for aurea)
P 0. 8
SPI D ATA O U T
M O S I
PW M C LO C K
M A T0.0
SPI D ATA R ETU R N
M I S O
BLAN K
M A T1.0
PR O G
t bd
C S EEPR O M
t bd
TEM P
P 0. 10
18310_204_090318.eps
090318
A m b ilig h t m o d u le 2
S o ut S in
D R IV E R
SPI d ata return
SPI c lo c k (SC LK)
SPI latc h (XLAT )
PR O G (VPR G )
BLAN K
PW M C LO C K ( G SC LK)
Figure 7-9 SPI communication between ARM controller and LED drivers
For debugging purposes, the working principle is given below:
• At start-up the controller will read-out matrix data from the
EEPROM devices (via SPI DATA RETURN)
• Before operation, the driver current is set via SPI, with
driver in DC mode
• During normal operation the controller receives RGB-,
configuration-, operation mode- and topology data via I
• The controller converts the I
to SPI LED data
• Via data return the controller receives error data (if
applicable).
Also PWM clock and BLANK signals are generated by the
controller. The controller can be reprogrammed via I
USB). The controller can receive matrix values via I
will be stored in the EEPROM of each AL module via the SPI
bus. The temperature sensor in each AL module controls the
TEMP line; in case of a too high temperature the controller will
reduce the overall brightness.
7.8.2 LED driver communication (via SPI bus)
Refer to Figure 7-9
ARM controller and the LED drivers on the AL boards, and the
LED drivers and the EEPROMs on the AL boards.
S o ut
L E D
2
Am bilight m odule 1
T E M P
S E N S O R
ARM
Figure 7-10 Communication between ARM controller and
Each AL board is equipped with a temperature sensor. If one of
the sensors detects a temperature over the threshold, the
TEMP line is pulled LOW which results in brightness reduction.
LC9.1A LA 7.
2
C RGB data via the matrixes
below for signal interfacing between the
A m b ilig h t m o d u le N
S in S o ut
L E D
D R IV E R
N
18310_205_090318.eps
Am bilight m odule 2 Am bilight m odule N
V c c V c c
Pull-up Pull-up
T E M P
S E N S O R
temperature sensor
EN 35
2
C
2
C (via
2
C, which
090318
V c c
Pull-up
T E M P
S E N S O R
18310_206_090318.eps
090318
2009-Apr-10