Motorola Symbol PL4507, Руководство по интеграции

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Getting Started 1 - 3
Marvell PXA320 Processor
The digital system is built on a Marvell PXA320 (Intel XScale
®
) super-pipelined RISC microarchitecture core. The
major features of the core are:
•
CPU clock speed up to 624 MHz with external DDR SDRAM bus speed of 133 MHz.
•
32 KB instruction/32 KB data L1 cache, 256 KB unified L2 cache, 728 KB internal SRAM.
Power Management
The Symbol PL4507 has various power management options depending on the host interface.
USB (SNAPI, USB HID Keyboard, etc.)
The PL4507 automatically manages its power usage, including USB suspend mode. Additionally, when drawing
power from the USB bus, the PL4507 and SE4500 do not exceed the USB limit of 500 mA (see
Interfaces on page
1-4 ).
SSI or RS-232
When using SSI or any RS-232 host interface, set the PL4507 to use one of the following power modes:
•
Continuous Power : The PL4507 is fully awake and running, even when not in a decode session.
•
Low Power (default): The PL4507 draws less current at idle than when in Continuous Power mode, and is
more suitable for battery-powered applications. See Technical Specifications on page 1-7 .
NOTE The PL4507 does not use Low Power mode when connected to a USB-based host.
Table 1-1
Methods of Placing the Symbol PL4507 into Low Power Mode
Action Behavior
Set the Power Mode parameter to Low Power
(see
Power Mode (RS-232 Hosts Only) on page
4-12 )
The PL4507 enters Low Power mode automatically
whenever possible.
Send the SLEEP command
(see
Table 6-1 on page 6-2 )
The PL4507 enters Low Power mode only once, as soon as
possible.
Note: All Wake Up signals (see Table 1-2 ) must be inactive to enter Low Power mode.