UM0592

Getting started

Doc ID 15036 Rev 1

7/22

1.4.2

USB

The EVAL-STR910 demonstration board supports USB 2.0 compliant full-speed

communication via a USB type-B connector (CN3). The ESD protection device U6

(USBLC6-2P6) is connected between CN3 and the microcontroller. The USBLC6-2P6 is a

monolithic application-specific device dedicated to ESD protection of high-speed interfaces

such as USB 2.0, Ethernet links and video lines. Two clock sources are available for the

USB:

●

PLL generated clock from the STR91xF

●

External oscillator U12

●

Clock source is selected by setting JP17.

1.4.3

Selection

Table 2.

Clock source setting

Jumper

Description

JP17

Enables the external USB 48 MHz clock source.

To use an external oscillator via P27 of the STR91xF for the USB clock

input, JP17 is fitted.

To use the internal clock of the STR91xF, JP17 is not fitted

Default setting: not fitted

JP9

Fit the jumper between pin 1 and 2 of JP9. 1.5 k

controlled by this jumper.

Table 3.

Jumper selection

Jumper

Description

J7

HDD_DMACK signal is used by the host in response to DMARQ to initiate DMA

transfer. For PIO mode transfer this signal is not used.

– Current version does not support the DMA mode transfer.

J11

– 1:2 to select P76 as HDD_CS1, fit jumper into pin 1 and 2 of J11

– 2:3 to select P55 as HDD_CS1, fit jumper into pin 2 and 3 of J11. Current

version does not support the DMA mode transfer