Datasheet

Conversion Clock and BYTE Control
3-2
3.1 Conversion Clock and BYTE Control
Jumpers W5–W7 control the clock divide and parallel data format of the
ADS8342. W6 and W7 connect to CLKDIV0 and CLKDIV1 respectively and
perform the following actions:
Jumper
Action
W6 W7
Action
open open External conversion clock (20MHz MAX) divided by 8
open closed External conversion clock (20MHz MAX) divided by 4
closed open External conversion clock (10MHz MAX) divided by 2
closed closed External conversion clock (5MHz MAX) divided by 1
Jumper W5 controls the BYTE pin of the ADS8342. When closed, the
ADS8342 operates in 16 bit output or word mode. When open, the ADS8342
operates in BYTE mode and data is accessed by reading D0-D7 twice.
3.2 Parallel Control
The ADS8342 modular EVM interfaces to multiple control platforms. Samtec
part numbers SSW-110-22-F-D-VS-K and TSM-110-01-T-DV-P provide a
10-pin dual-row header/socket combination at J4. This header/socket
combination provides access to the RD, CONVST, and clock pins of the
ADS8342.
Signal Description
J4.1 DC_CSa Daughter card chip select—active low signal used to access the EVM
J4.3 WR Processor write strobe—active low signal used to initiate a conversion
J4.5 RD Processor read strobe—active low signal used to access parallel data
J4.7 EVM_A0 EVM address line 0—used in conjunction with EVM_A1 to chip select the ADS8342
J4.9 EVM_A1 EVM address line 1—used in conjunction with EVM_A0 to chip select the ADS8342
J4.11 EVM_A2 EVM address line 2—connects to the ADS8342 A1 pin, controls channel read
J4.13 EVM_A3 EVM address line 3—connects to the ADS8342 A1 pin, controls channel read
J4.15 EVM_A4 EVM address line 4—not used
J4.17 TOUT Processor timer output—optional conversion clock source
J4.19 INT Processor interrupt input—connects to the ADS8342 BUSY pin
3.3 Parallel Data
The ADS8342 modular EVM uses Samtec part numbers
SSW-116-22-F-D-VS-K and TSM-116-01-T-DV-P to provide a 16-pin dual-row
header/socket combination at J3. This header/socket combination provides
access to the parallel data pins of the ADS8342. Data line D0 is connected to
J3 pin 1. Data lines 1-15 are located on odd-numbered pins 3-31 respectively.
Even-numbered pins 2-32 are connected to digital ground.