Datasheet
AD8197B
Rev. 0 | Page 22 of 28
HIGH SPEED DEVICE MODES REGISTER
PP_EN: High Speed (TMDS) Channels Enable Bit
Table 19. PP_EN Description
PP_EN Description
0 High speed channels off, low power/standby mode
1 High speed channels on
PP_CH[1:0]: High Speed (TMDS) Switch Source Select Bus
Table 20. PP_CH Mapping
PP_CH[1:0] O[3:0] Description
00 A[3:0]
High Speed Source A switched to
output
01 B[3:0]
High Speed Source B switched to
output
10 C[3:0]
High Speed Source C switched to
output
11 D[3:0]
High Speed Source D switched to
output
Note that after changing the status of the channel selection
(PP_CH[1:0]0), it is necessary to assert a low logic level to
RESET to ensure that the channel select status is properly
updated.
AUXILIARY DEVICE MODES REGISTER
PP_CH[1:0]: Auxiliary Switch Source Select Bus
Table 21. PP_CH Mapping
PP_CH[1:0] AUX_COM[3:0] Description
00 AUX_A[3:0]
Auxiliary Source A switched to
output
01 AUX_B[3:0]
Auxiliary Source B switched to
output
10 AUX_C[3:0]
Auxiliary Source C switched to
output
11 AUX_D[3:0]
Auxiliary Source D switched to
output
INPUT TERMINATION RESISTOR CONTROL
REGISTER 1 AND REGISTER 2
High speed input (TMDS) channels input terminations are off
when using the parallel interface. This can be changed only via
serial programming.
RECEIVE EQUALIZER REGISTER 1 AND REGISTER 2
PP_EQ: High Speed (TMDS) Inputs Equalization Level
Select Bit (For All TMDS Input Channels)
The input equalization cannot be set individually (per channel)
when using the parallel interface; one equalization setting
affects all input channels.
Table 22. PP_EQ Description
PP_EQ Description
0 Low equalization (6 dB)
1 High equalization (12 dB)
TRANSMITTER SETTINGS REGISTER
PP_PE[1:0]: High Speed (TMDS) Output Pre-Emphasis
Level Select Bus (For All TMDS Channels)
Table 23. PP_PE[1:0] Description
PP_PE[1:0] Description
00 No pre-emphasis (0 dB)
01 Low pre-emphasis (2 dB)
10 Medium pre-emphasis (4 dB)
11 High pre-emphasis (6 dB)
PP_OTO: High Speed (TMDS) Output Termination On/Off
Select Bit (For All TMDS Channels)
Table 24. PP_OTO Description
PP_OTO Description
0 Output termination off
1 Output termination on
PP_OCL: High Speed (TMDS) Output Current Level Select
Bit (For All TMDS Channels)
Table 25. TX_OCL Description
PP_OCL Description
0 Output current set to 10 mA
1 Output current set to 20 mA