ADS7870 Datasheet, PDF (27/27 Pages) Burr-Brown (TI) – 12-Bit ADC, MUX, PGA and Internal Reference DATA ACQUISITION SYSTEM

Figure 18 shows a typical physical connection between an
M68HC11 and a ADS7870. A pull-up resister on DOUT
may be needed to keep DOUT from floating during write
operations. CS may be permanently tied low if desired, but
the ADS7870 must be the only peripheral.
Intel 80C51
The Intel 80C51 operated in serial port Mode 0 has a two-
wire (three-wire if an additional I/O pin is used for CS) serial
interface. The TXD pin provides the clock for the serial
interface and RXD serves as the data input and output. The
data is transferred LSB first. Best compatibility is achieved
by connecting the RISE/FALL pin of the ADS7870 high
(rising edge of SCLK active). In the Interface Configuration
Register, the LSB bit and the 8051 bit should be set. The 2W
bit should also be set. The first instruction after power-on or
reset should be a write operation to the Interface Configura-
tion Register.
Figure 19 shows a typical physical connection between an
80C51 and an ADS7870. CS may be permanently tied low
if desired, but the ADS7870 must be the only peripheral.
M68HC11
MOSI
MISO
SCK
SS
ADS7870
DIN
DOUT
SCLK
CS
FIGURE 18. Connection of M68HC11 to the ADS7870.
80C51
RXD
TXD
Px.x
ADS7870
DIN
DOUT
SCLK
CS
FIGURE 19. Connection of 80C51 to the ADS7870.
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ADS7870