Datasheet

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OUTPUT CODE (DB15 … DB0)
HOLDA
HOLDC
BUSY
CS
BYTE
RD
CS
RD
BYTE
A0 A0 A1 A1 B0 B0 B1 C0 C1 A0
LOW HIGH LOW HIGH LOW HIGH
ADS7864
SBAS141A – SEPTEMBER 2000 – REVISED MARCH 2005
Table 2. Channel Truth Table
DATA CHANNEL DB14 DB13 DB12
The ADS7864 has a 16-bit output word. DB15 is ‘1’ if
A0 0 0 0
the output contains valid data. This is important for
the FIFO mode. Valid Data can be read until DB15
A1 0 0 1
switches to 0. DB14, DB13 and DB12 store channel
B0 0 1 0
information as indicated in Table 2 (Channel Truth
B1 0 1 1
Table). The 12-bit output data is stored from DB11
C0 1 0 0
(MSB) to DB0 (LSB).
C1 1 0 1
BYTE—If there is only an 8-bit bus available on a
board, then Byte can be set high (see Figure 29 and
Figure 30 ). In this case, the lower eight bits can be
read at the output pins DB7 to DB0 at the first RD
signal, and the higher bits after the second RD signal.
Figure 29. Reading Data in Cycling Mode
Figure 30. Reading Data in Cycling Mode
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