2.3.3. Power supply

Power is supplied to the Multi-ICE interface unit through:

The minimum target power supply voltage is 2V, and the maximum is 5V. You can calculate the approximate operating current using the formula:

A graph of this function is shown in Figure 2.4. On power-up, the Multi-ICE interface unit draws more current than the graph shows, and the power supply must be capable of delivering this. As a general guide, 440mA at 3.3V has been measured. If the target supply voltage or its current capability is too low, you must use the external power input jack.

You can provide power to the Multi-ICE interface unit using the power input jack from a consumer power transformer (sometimes referred to as a wall-wart). The transformer must be rated to supply between 9 and 12V at 500mA minimum. If you use the external power jack, you can connect to targets using logic voltages of 1V to 5V.

Note

The original EmbeddedICE interface unit literature stated that the target power supply Vdd must have a series resistor in the feed to the JTAG interface power pin. For Multi-ICE to operate correctly from the target power supply, this resistor must not be present.

Shorting out this resistor does not affect the operation of the ARM EmbeddedICE Interface Unit, and, on target boards built by ARM Limited, does not affect the operation of the target board.

Figure 2.4. Multi-ICE current consumption with voltage

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