P&E Microcomputer Systems Cyclone LC Series, Руководство пользователя

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User Manual For Cyclone LC Programmers 34
4 TARGET POWER MANAGEMENT
Different target devices may require different power schemes which depend on the design of the
target board, target voltages, and even the device architecture. PEmicro has designed the
Cyclone LC to be capable of powering a target before, during, and after programming. Power can
be sourced at many voltage levels from the Cyclone itself, or sourced by an external power supply
and switched by the Cyclone.
Figure 4-1: Five different paths to power a target
The versatility of the Cyclone power scheme gives the user the utmost flexibility, and includes the
following features:
• Provides power through a power jack or through the debug connector
• Provides internally generated voltage from 1.6v-5.5v at up to 500mA
• Switches an external power supply voltage, up to 24V at 1amp
• Selectively powers the target before, during, and after programming
• Powers down the target connections between programming operations
• Uses power switching to aid entry into debug mode for certain targets
• Provides target voltage and current measurement capabilities
If target power is required, each target board may vary where the power is sourced from, externally
or internally, and how it is channeled to the target: through the debug header or to a separate
connector to the board. Power that is passed through and managed by the Cyclone goes through
power relays so it can be power cycled. This is extremely useful because it also allows the power
to be off during setup and automatically powered on by the Cyclone for programming. For some
devices, the process of entering debug mode requires that the device be powered down and
powered back up. Power can also be left in a desired power state, either on or off.
4.1 Cyclone Configuration
There are two different places Power Management is configured and they should be matched :
first, by the jumpers on the Cyclone LC , and second, in the setup of the programming image.
The Cyclone jumpers are the most important because they are the physical connection to the
target. The Cyclone has an easy access panel that reveals debug header connections for a variety
of different architectures, and a 2x4 jumper block for configuring power management of the target.
The specific location of the jumpers is indicated by the label POWER JUMPERS in
Figure 4-3 .
This set of 4 jumpers can be used to set 5 different power management schemes for the target.