Pl4407 Decoder; Power Management (Symbol Ms4404 Only) - Motorola Symbol MS4404 Integration Manual

PL4407 Decoder

ARM9-Based Processor
The digital system is built on an ARM9 Harvard architecture core, 32 bit RISC engine with a five-stage pipeline. The
major features of the core are:
•
Programmable speed up to 150 MHz with an adjustable external bus speed up to 96 MHz.
•
16K instruction and data cache (64-way set associative).
•
Flexible internal bus architecture that supports DMA operations from any peripheral module to the core or to
another peripheral port including main memory.
Implementation of an enhanced Memory Management Unit (MMU).
•
Main Memory
The two available PL4407 microprocessor designs are:
•
PL4407-x100: 32-bit external bus interface to 8 MB of PC100-compliant SDRAM, classified as Mobile
SDRAM due to its lower operating current and enhanced power-down modes; internally configured as
4 banks of 512 kb x 32 bits.
•
PL4407-x200: 32-bit external bus interface to 16 MB of Mobile SDRAM; internally configured as
4 banks of 1024 Kb x 32 bits.

Power Management (Symbol MS4404 Only)

NOTE This section does not apply to the USB interface. USB supports low power mode defined in the USB
specification.
The Symbol MS4404 has two power modes:
•
Continuous Power
Low Power.
•
In Continuous Power mode, the Symbol MS4404 system always runs, even when not in a decode session.
In Low Power mode (the default power mode), the Symbol MS4404 draw less current than when in Continuous
Power mode, and is more suitable for battery-powered applications. In this mode the Symbol MS4404 enters Low
Power mode whenever possible. You must awaken the Symbol MS4404 from Low Power mode before performing
any functions.
Table 1-1 describes how to put the Symbol MS4404 into Low Power mode;
Completely removing power from the Symbol MS4404 is not recommended; this should not be necessary as in Low
Power mode the Symbol MS4404 consumes very little power (see
Placing the Symbol MS4404 into Low Power Mode
Table 1-1
Set the Power Mode parameter to Low Power
(see Power Mode on page
Send the serial SLEEP command (see the Simple
Serial Interface (SSI) Programmer Guide).
Note: All Wake Up signals (see
wakes, at least 1 second (programmable time) must elapse before it re-enters Low Power mode.
Action
6-9).
Table 1-2) must be inactive to enter Low Power mode. Once the Symbol MS4404
Table 1-2
Table 1-1).
Behavior
The Symbol MS4404 enters Low Power mode automatically
whenever possible.
The Symbol MS4404 enters Low Power mode only once, as
soon as possible.
Getting Started 1 - 5
describes how to awaken it.