TLC5945
www.ti.com
SLVS755–MARCH 2007
n = 0 to 15
Grayscale data for all OUTn
The input shift register enters grayscale data into the grayscale register for all channels simultaneously. The
complete grayscale data format consists of 16 x 12 bit words, which forms a 192-bit wide data packet (see
Figure 11). The data packet must be clocked in with the MSB first.
MSB
0
LSB
191
11
GS 15.0 GS 14.11
GS OUT15
12
179
180
GS 15.11
GS 1.0 GS 0.11
GS 0.0
GS OUT14 − GS OUT1
GS OUT0
Figure 11. Grayscale Data Packet Format
When MODE is set to GND, the TLC5945 enters the grayscale data input mode. The device switches the input
shift register to 192-bit width. After all data is clocked in, a rising edge of the XLAT signal latches the data into
the grayscale register (see Figure 12). New grayscale data immediately becomes valid at the rising edge of the
XLAT signal; therefore, new grayscale data should be latched at the end of a grayscale cycle when BLANK is
high. The first GS data input cycle after dot correction requires an additional SCLK pulse after the XLAT signal
to complete the grayscale update cycle. All GS data in the input shift register is replaced with status information
data (SID) after updating the grayscale register.
DC Mode Data
Input Cycle
First GS Mode Data
Input Cycle After DC Data Input Cycle
Following GS Mode Data
Input Cycle
MODE
t
h3
t
h3
t
su3
XLAT
SIN
t
wh2
GS + 1
MSB
GS n + 1
LSB
GS
MSB
DC
LSB
GS
LSB
t
h1
t
h2
t
su1
t
su2
96
1
192
193
1
192
SCLK
SOUT
t
pd0
SID n + 1
MSB
SID
MSB−1
SID
MSB
SID
LSB
DC
MSB
DC n
LSB
GS
MSB
X
X
Figure 12. Grayscale Data Input Timing Chart
STATUS INFORMATION OUTPUT
The TLC5945 does have a status information register, which can be accessed in grayscale mode (MODE =
GND). After the XLAT signal latches the data into the GS register, the input shift register data is replaced with
status information data (SID) of the device (see Figure 12). LOD, TEF, and dot-correction register data can be
read out at the SOUT pin. The status information data packet is 192 bits wide. Bits 0 – 15 contain the LOD
status of each channel. Bit 16 contains the TEF status. Bits 24 – 119 contain the data of the dot-correction
register. The remaining bits are reserved. The complete status information data packet is shown in Figure 13.
SOUT outputs the MSB of the SID at the same time the SID are stored in the SID register, as shown in
16
Submit Documentation Feedback
TI [ TEXAS INSTRUMENTS ]
