App Note 301 - Chaining Apex Development Boards

App Note 301 - Chaining Apex Development Boards


1. Purpose

This application note shows how to connect three Anadigm Apex development boards in a chain. The diagram identifies the inter-board connections, PIC and oscillator jumper settings, and shared power and ground connections.

The board on the right connects to the PC. The other boards connect through the inter-board headers, with their PIC controllers disabled. Only one board’s 16 MHz oscillator remains enabled.

2. Board Connection Diagram

Figure 1 reproduces the complete annotated diagram from the application note. Open the full-size image to read the board labels and trace the connections.

3. Connecting the Boards

3.1 PC Connection and PIC Controller Settings
Connect the PC to the board on the right, as shown in Figure 1. The diagram identifies this board as having the default jumper settings.

• On the board connected to the PC, position J1 to the right.
• On every other board, move J1 to the left to disable its PIC controller.

3.2 Inter-board Connections
Use nine jumpers between each adjacent pair of boards, following the header positions shown in Figure 1. The illustrated three-board chain has two sets of nine inter-board jumpers.

3.3 Clock Settings
Fit a jumper on J7 on all boards except one to disable their 16 MHz oscillators. Leave the oscillator-disable jumper off J7 on one board only. In the illustrated arrangement, this is the right-hand board connected to the PC.

3.4 CS1 Jumper Setting
The original diagram instructs the user to remove the CS1 jumper from all boards except the first board on the right.

Source clarification: The annotation reads “Remove CS1 jumper from J7 on all boards except the first board (on the right).” Other annotations also refer to J7 for oscillator control. Confirm the CS1 header location against the manual and silkscreen for your board revision before changing this jumper.

4. Power and Ground Connections

Connect power and ground in common to all boards, following the wiring shown in Figure 1. Keep the power and ground leads as short as possible.

Add extra ground links between the boards. The source diagram recommends multiple additional ground links and specifies that these links should also be kept as short as possible.

5. Configuration Checklist

• The PC is connected to the right-hand board.
• J1 is positioned to the right on the PC-connected board and to the left on all other boards.
• Each adjacent pair of boards is connected by nine jumpers in the positions shown.
• Only one board’s 16 MHz oscillator is enabled.
• The CS1 setting follows the diagram, with the header identity checked against the relevant board documentation.
• All boards share power and ground, with short leads and additional short ground links.

Source: AN231001-U301, Chaining Apex. For assistance with a specific board revision, contact Okika Devices Support.