DS90UB925Q Datasheet, PDF (17/41 Pages) Texas Instruments – 5 - 85 MHz 24-bit Color FPD-Link III Serializer with Bidirectional Control Channel

DS90UB925Q
TABLE 1. Configuration Select (MODE_SEL)
# Ideal Ratio
V_R4/V_DD33
Ideal V_R4
(V)
Suggested
Resistor R3
kΩ (1% tol)
Suggested
Resistor R4
kΩ (1% tol)
LFMODE
Repeater
Backward
Compatible
I2S Channel
B
(18–bit
Mode)
1
0
0
Open
40.2 or Any
L
L
L
L
2
0.121
0.399
294
40.2
L
L
L
H
3
0.152
0.502
280
49.9
L
H
L
L
4
0.242
0.799
240
76.8
L
H
L
H
5
0.311
1.026
226
102
H
L
L
L
6
0.402
1.327
196
130
H
L
L
H
7
0.492
1.624
169
165
H
H
L
L
8
0.583
1.924
137
191
H
H
L
H
9
0.629
2.076
124
210
L
L
H
L
10 0.727
2.399
90.9
243
H
L
H
L
LFMODE: L = 15 – 85 MHz (Default); H = 5 – <15 MHz
Repeater: L = Repeater Off (Default); H = Repeater On
Backward Compatible: L = Backward Compatible Off (Default); H = Backward Compatible On to 906/908 (15 - 65MHz)
I2S Channel B: L = I2S Channel B Off, Normal 24-bit RGB Mode (Default); H = I2S Channel B On, 18-bit RGB Mode with I2S_DB
Enabled.
GPIO[3:0] and GPO_REG[8:4]
In 18-bit RGB operation mode, the optional R[1:0] and G[1:0] of the DS90UB925Q can be used as the general purpose IOs GPIO
[3:0] in either forward channel (Inputs) or back channel (Outputs) application.
GPIO[3:0] Enable Sequence
See Table 2 for the GPIO enable sequencing.
Step 1: Enable the 18-bit mode either through the configuration register bit Table 6 on DS90UB925Q only. DS90UB926Q is
automatically configured as in the 18-bit mode.
Step 2: To enable GPIO3 forward channel, write 0x03 to address 0x0F on DS90UB925Q, then write 0x05 to address 0x1F on
DS90UB926Q.
#
Description
1
Enable 18-bit
mode
2
GPIO3
3
GPIO2
4
GPIO1
5
GPIO0
TABLE 2. GPIO Enable Sequencing Table
Device
DS90UB925Q
DS90UB926Q
DS90UB925Q
DS90UB926Q
DS90UB925Q
DS90UB926Q
DS90UB925Q
DS90UB926Q
DS90UB925Q
DS90UB926Q
Forward Channel
0x12 = 0x04
Auto Load from DS90UB925Q
0x0F = 0x03
0x1F = 0x05
0x0E = 0x30
0x1E = 0x50
0x0E = 0x03
0x1E = 0x05
0x0D = 0x93
0x1D = 0x95
Back Channel
0x12 = 0x04
Auto Load from DS90UB925Q
0x0F = 0x05
0x1F = 0x03
0x0E = 0x50
0x1E = 0x30
0x0E = 0x05
0x0E = 0x05
0x0D = 0x95
0x1D = 0x93
GPO_REG[8:4] Enable Sequence
GPO_REG[8:4] are the outputs only pins. They must be programmed through the local register bits. See Table 3 for the GPO_REG
enable sequencing.
Step 1: Enable the 18-bit mode either through the configuration register bit on DS90UB925Q only. DS90UB926Q is automatically
configured as in the 18-bit mode.
Step 2: To enable GPO_REG8 outputs an “1”, write 0x90 to address 0x11 on DS90UB925Q.
Copyright © 1999-2012, Texas Instruments Incorporated
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