Channel Target-Powering Options

This section explains the three main target-powering scenarios for each channel on a 4-channel programming pod.

1) Target Self-Powered
2) Channel powers the MCU Vcc rail directly
3) Channel powers the board input through Vsys

Common Channel Connections

Each channel (1-4) has a set of signals which are connected to each target to be programmed:

• Vcc - Connected to the target MCU Vcc rail, One per Channel
• Vsys - Optional board-level power output, One per Channel
• I/O 1-8 - Bidirectional programming/debug signals, Eight Signals per Channel
• GND - Target ground reference, Shared by all channels
• The ground (GND) of each channel is connected to the ground of the other channels and of the Cyclone MultiChannel Programmer.

The only difference between the three power scenarios is how power is provided or monitored by the Vcc and Vsys connections.

Quick Comparison

Option	Power source	Vcc role	Vsys role
Option	Power source	Vcc role	Vsys role
1	Target self-powered	Sense MCU Vcc	Not connected
2	Channel powers MCU Vcc directly	Output to MCU Vcc	Not connected
3	Channel powers board input	Sense MCU Vcc	Output to board regulator input

Practical notes:

• Ground and debug I/O wiring stay the same in all three modes
• The difference is only how power is routed
• In Option 3, Vcc still shows the actual MCU rail after regulation

Option 1 - Target Self-Powered

Typical use: Most common setup. The target board already has its own power source.

Connections:
- Connect target GND to channel GND
- Connect target MCU Vcc to channel Vcc
- Leave channel Vsys unconnected
- Connect target debug signals to I/O 1-8

Behavior:
- The channel does not supply power
- The channel senses the target MCU voltage automatically by measuring Vcc

Option 2 - Channel powers the MCU Vcc rail directly

For models which can supply Vcc to the target. Typical use: The channel should directly supply the target MCU power rail.

Connections:
- Connect target GND to channel GND
- Connect target MCU Vcc to channel Vcc
- Leave channel Vsys unconnected
- Connect target debug signals to I/O 1-8

Behavior: - The channel drives the MCU Vcc line through Vcc
- Output range is 1.6 V to 5.2 V

Option 3 - Channel powers the board input through Vsys

For models which can supply Vsys to the target. Typical use: The board should be powered through its normal board input, such as a regulator input or VIN.

Connections:
- Connect target GND to channel GND
- Connect target MCU Vcc to channel Vcc
- Connect target board power input to channel Vsys
- Connect target debug signals to I/O 1-8

Behavior:
- The channel drives Vsys
- Output range is 1.8 V to 15.0 V
- The channel senses the actual MCU Vcc automatically by measuring Vcc