Analog Devices ADSP-21992 EZ-KIT LITE, Системное руководство

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System Architecture
3-8 ADSP-21992 EZ-KIT Lite Evaluation System Manual
SPI Digital-to-Analog Converter
An 8-channel, serial, 12-bit DAC (
A9
) is provided on the ADSP-21992
EZ-KIT Lite board. The
PF2
/
SPISEL2
pin of the ADSP-21992 is used to
select the DAC (AD5328BRU) to be active on the SPI interface.
PF3
is
used to update the DAC registers. Two jumpers (
JP15
and
JP16
) are used
to disable the DACs when the
PF2
and
PF3
pins are being used as program-
mable flag pins.
The outputs of the DAC are available at connector
P5
. Refer to Table 3-5
on page 3-20 for the configuration of
P5
.
CAN Interface
A CAN transceiver IC (
U2
) is provided on the SPI Interface. The CAN
transceiver IC converts the input and output to the CAN bus voltages lev-
els. Connectors
P12
and
P13
provide connections to the user’s CAN bus
and allow easy daisy-chaining of CAN devices. CAN bus termination of
120 ohms can be provided by closing jumper
JP23
.
Serial Port (SPORT) Interface
All programmable flag pins are available on connector
P8
. Refer to
Table 3-3 on page 3-19 for the configuration of
P8
.
Circuitry is also provided on the ADSP-21992 EZ-KIT Lite board to
allow you to use the SPORT for RS-232 emulation. An ADM3202ARN
line driver/receiver (
A4
) is provided to convert the SPORT signals to the
appropriate ±10V levels suitable for the UART connection to the PC. A
standard 9-pin female D-sub socket,
P9
, is provided on the ADSP-21992
EZ-KIT Lite board.
Jumpers
JP18
,
JP19
, and
JP20
connect the SPORT signals to the RS-232
circuitry. All three jumpers must be closed to use the RS-232 interface
circuitry.