LTC1197 Linear Technology, LTC1197 Datasheet - Page 21

• Manufacturer Part Number: LTC1197
• Description: 10-Bit/ 500ksps ADCs in MSOP with Auto Shutdown
• Manufacturer: Linear Technology

MICROPROCESSOR INTERFACES
The LTC1197/LTC1197L/LTC1199/LTC1199L can inter-
face directly (without external hardware to most popular
microprocessor (MPU) synchronous serial formats (see
Table 1). If an MPU without a dedicated serial port is used,
then three or four of the MPU’s parallel port lines can be
programmed to form the serial link. Included here is one
serial interface example and one example showing a
parallel port programmed to form the serial interface.
TYPICAL
A
PPLICATI
Table 1. Microprocessor with Hardware Serial Interfaces
Compatible with the LTC1197/LTC1197L/LTC1199/LTC1199L
MICROWIRE and MICROWIRE/PLUS are trademarks of
National Semiconductor Corp.
O
Motorola
RCA
Hitachi
National Semiconductor
Texas Instruments
Microchip Technology
MC6805S2,S3
MC68HC11
MC68HC05
CDP68HC05
HD6301
HD6303
HD6305
HD63701
HD63705
HD64180
COP400 Family
COP800 Family
NSC8050U
HPC16000 Family
TMS7000 Family
TMS320 Family
PIC16C60 Family
PIC16C70 Family
U
PART NUMBER
S
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
SPI, SCI Synchronous
SPI, SCI Synchronous
Motorola SPI (MC68HC05C4, MC68HC11)
The MC68HC05C4 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. With two 8-bit trans-
fers, the A/D result is read into the MPU. The first 8-bit
transfer sends the D
two ADC MSBs (B9 and B8) into the MPU. The second 8-
bit transfer clocks the next 8 bits, B7 through B0, of the
ADC into the MPU.
ANDing the first MPU received byte with 03Hex clears the
six MSBs. Notice how the position of the start bit in the D
word is used to position the A/D result so that it is right-
justified in two memory locations.
TYPE OF INTERFACE
TM
TM
IN
word to the LTC1199 and clocks the
LTC1197/LTC1197L
LTC1199/LTC1199L
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IN