AFE5804_17 Datasheet, PDF (41/63 Pages) Texas Instruments – FULLY-INTEGRATED, 8-CHANNEL ANALOG FRONT-END FOR ULTRASOUND 12-Bit, 40MSPS, 101mW/Channel

AFE5804
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LVDS TEST PATTERNS
SBOS442C – JUNE 2008 – REVISED OCTOBER 2011
ADDRESS
IN HEX
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
X
0
0
0
X
0
25
0
0
X
X
X
X
X
26
X
X
X
X
X
X
X
X
X
X
27
X
X
X
X
X
X
X
X
X
X
0
X
45
X
0
NAME
EN_RAMP
DUALCUSTOM_PAT
SINGLE_CUSTOM_PAT
BITS_CUSTOM1<11:10>
BITS_CUSTOM2<11:10>
BITS_CUSTOM1<9:0>
BITS_CUSTOM2<9:0>
PAT_DESKEW
PAT_SYNC
The AFE5804 can output a variety of test patterns on the LVDS outputs. These test patterns replace the normal
ADC data output. Setting EN_RAMP to '1' causes all the channels to output a repeating full-scale ramp pattern.
The ramp increments from zero code to full-scale code in steps of 1LSB every clock cycle. After hitting the
full-scale code, it returns back to zero code and ramps again.
The device can also be programmed to output a constant code by setting SINGLE_CUSTOM_PAT to '1', and
programming the desired code in BITS_CUSTOM1<11:0>. In this mode, BITS_CUSTOM<11:0> take the place of
the 12-bit ADC data at the output, and are controlled by LSB-first and MSB-first modes in the same way as
normal ADC data are.
The device may also be made to toggle between two consecutive codes by programming DUAL_CUSTOM_PAT
to '1'. The two codes are represented by the contents of BITS_CUSTOM1<11:0> and BITS_CUSTOM2<11:0>.
In addition to custom patterns, the device may also be made to output two preset patterns:
1. Deskew patten: Set using PAT_DESKEW, this mode replaces the 12-bit ADC output D<11:0> with the
010101010101 word.
2. Sync pattern: Set using PAT_SYNC, the normal ADC word is replaced by a fixed 111111000000 word.
Note that only one of the above patterns should be active at any given instant.
Copyright © 2008–2011, Texas Instruments Incorporated
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