System overview

UM0581

8/26

Doc ID 14961 Rev 1

2

System overview

2.1

General description of product architecture

2.2

System architecture description

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The board works as a USB-based hard disk implemented on the STR912FAW44

microcontroller

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The STR912FAW44 parallel interface to hard disk demonstration board consists of two

main sections. First the interface of the hard disk to STR912FAW44 through an external

memory interface (EMI) and second, the hard disk appears as a removable drive on the

PC which is made possible by the USB mass-storage implementation

●

The hard disk is connected to STR912FAW44 with a built-in EMI module. The EMI is

used in 16-bit MUX mode

●

The onboard power supply unit can be used for powering the hard disk. This board

works with a PC which is the USB host

●

In addition to the onboard power supply, a separate SMPS power supply can be used

to power the board as well as the hard disk

●

LEDs available on the demonstration board indicate read or write operation

●

JTAG interface for debugging purposes

●

For ESD protection the device is connected between the USB connector and

STR912FAW44

●

The board consists of a dual, ultra-low reset supervisor and monitors the reset level of

the STR912FAW44

Figure 3.

System architecture of the demonstration board

AM01271v1

USB Type

B

connector

ESD

Protection

STR9

JTAG

LED’s

On board

Power supply

Unit

RESET

Supervisor

HARD-

DISK

USB

CABLE

SMPS

Connector