Datasheet

ADC1212D_SER All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 2 — 4 March 2011 28 of 42
NXP Semiconductors
ADC1212D series
Dual 12-bit ADC: CMOS or LVDS DDR digital outputs
11.5.6 Test patterns
For test purposes, the ADC1212D can be configured to transmit one of a number of
predefined test patterns (via bits TESTPAT_SEL[2:0]; see Table 27
). A custom test pattern
can be defined by the user (TESTPAT_USER[11:4]; see Table 28
and
TESTPAT_USER[3:0]; see Table 29
) and is selected when TESTPAT_SEL[2:0] = 101.
The selected test pattern is transmitted regardless of the analog input.
11.5.7 Output codes versus input voltage
11.6 Serial Peripheral Interface (SPI)
11.6.1 Register description
The ADC1212D serial interface is a synchronous serial communications port that allows
easy interfacing with many commonly used microprocessors. It provides access to the
registers that control the operation of the chip.
This interface is configured as a 3-wire type (SDIO as bidirectional pin).
Pin SCLK is the serial clock input and CS
is the chip select pin.
Each read/write operation is initiated by a LOW level on CS
. A minimum of three bytes is
transmitted (two instruction bytes and at least one data byte). The number of data bytes is
determined by the value of bits W1 and W2 (see Table 18
).
Table 16. Output codes
V
INAP
 V
INAM
/
V
INBP
 V
INBM
Offset binary Two’s complement OTRA/OTRB
pin
< 1 0000 0000 0000 1000 0000 0000 1
1.0000000 0000 0000 0000 1000 0000 0000 0
0.9995117 0000 0000 0001 1000 0000 0001 0
0.9990234 0000 0000 0010 1000 0000 0010 0
0.9985352 0000 0000 0011 1000 0000 0011 0
0.9980469 0000 0000 0100 1000 0000 0100 0
.... .... .... 0
0.0009766 0111 1111 1110 1111 1111 1110 0
0.0004883 0111 1111 1111 1111 1111 1111 0
+0.0000000 1000 0000 0000 0000 0000 0000 0
+0.0004883 1000 0000 0001 0000 0000 0001 0
+0.0009766 1000 0000 0010 0000 0000 0010 0
.... .... .... 0
+0.9980469 1111 1111 1011 0111 1111 1011 0
+0.9985352 1111 1111 1100 0111 1111 1100 0
+0.9990234 1111 1111 1101 0111 1111 1101 0
+0.9995117 1111 1111 1110 0111 1111 1110 0
[phone] 0111 1111 1111 0
> [phone] 0111 1111 1111 1