LTC1285 LINER [Linear Technology], LTC1285 Datasheet - Page 20

• Manufacturer Part Number: LTC1285
• Description: 3V Micropower Sampling 12-Bit A/D Converters in SO-8 Packages
• Manufacturer: LINER [Linear Technology]

LTC1285/LTC1288
TYPICAL APPLICATIONS
MICROPROCESSOR INTERFACES
The LTC1285/LTC1288 can interface directly without ex-
ternal hardware to most popular microprocessor (MPU)
synchronous serial formats (see Table 1). If an MPU
without a dedicated serial port is used, then 3 or 4 of the
MPU's parallel port lines can be programmed to form the
serial link to the LTC1285/LTC1288. Included here is one
serial interface example and one example showing a
parallel port programmed to form the serial interface.
Motorola SPI (MC68HC11)
The MC68HC11 has been chosen as an example of an MPU
with a dedicated serial port. This MPU transfers data MSB
-first and in 8-bit increments. The D
register starts with the SPI process. With three 8-bit
transfers, the A/D result is read into the MPU. The second
8-bit transfer clocks B11 through B8 of the A/D conversion
result into the processor. The third 8-bit transfer clocks
the remaining bits, B7 through B0, into the MPU. The data
is right justified into two memory locations. ANDing the
second byte with OF
bits. This operation was not included in the code. It can be
inserted in the data gathering loop or outside the loop
when the data is processed.
MC68HC11 Code
In this example the D
a single-ended input to be applied to CHO. The conversion
result is output MSB-first.
20
IN
HEX
word configures the input MUX for
clears the four most significant
IN
U
word sent to the data
N
Table 1. Microprocessor with Hardware Serial Interfaces
Compatible with the LTC1286/LTC1298
* Requires external hardware
†
Motorola
RCA
Hitachi
National Semiconductor
Texas Instruments
Intel
MICROWIRE and MICROWIRE/PLUS are trademarks of
National Semiconductor Corp.
MC6805S2,S3
MC68HC11
MC68HC05
CDP68HC05
HD6305
HD63705
HD6301
HD63701
HD6303
HD64180
COP400 Family
COP800 Family
NS8050U
HPC16000 Family
TMS7002
TMS7042
TMS70C02
TMS70C42
TMS32011*
TMS32020
8051
PART NUMBER
SPI
SPI
SPI
SPI
SCI Synchronous
SCI Synchronous
SCI Synchronous
SCI Synchronous
SCI Synchronous
CSI/O
MICROWIRE
MICROWIRE/PLUS
MICROWIRE/PLUS
MICROWIRE/PLUS
Serial Port
Serial Port
Serial Port
Serial Port
Serial Port
Serial Port
Bit Manipulation on Parallel Port
TYPE OF INTERFACE
†
†
†
†