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AT8xC5122/23

4202E–SCR–06/06

• Endpoint enable

Before using an endpoint, this one should be enabled by setting the EPEN bit in the

UEPCONX register.

An endpoint which is not enabled won’t answer to any USB request. The Default Control

Endpoint (Endpoint 0) should always be enabled in order to answer to USB standard

requests.

• Endpoint type configuration

All Standard Endpoints can be configured in Control, Bulk, Interrupt or Isochronous

mode. The Ping-pong Endpoints can be configured in Bulk, Interrupt or Isochronous

mode. The configuration of an endpoint is performed by setting the field EPTYPE with

the following values:

– Control: EPTYPE = 00b

– Isochronous: EPTYPE = 01b

– Bulk: EPTYPE = 10b

– Interrupt: EPTYPE = 11b

The Endpoint 0 is the Default Control Endpoint and should always be configured in Con-

trol type.

• Endpoint direction configuration

For Bulk, Interrupt and Isochronous endpoints, the direction is defined with the EPDIR

bit of the UEPCONX register with the following values:

– IN:EPDIR = 1b

– OUT:EPDIR = 0b

For Control endpoints, the EPDIR bit has no effect.

• Summary of Endpoint Configuration:

Make sure to select the correct endpoint number in the UEPNUM register before

accessing to endpoint specific registers.

Table 62. Summary of Endpoint Configuration

Endpoint configuration EPEN EPDIR EPTYPE UEPCONX

Disabled 0b Xb XXb 0XXX XXXb

Control 1b Xb 00b 80h

Bulk-In 1b 1b 10b 86h

Bulk-Out 1b 0b 10b 82h

Interrupt-In 1b 1b 11b 87h

Interrupt-Out 1b 0b 11b 83h

Isochronous-In 1b 1b 01b 85h

Isochronous-Out 1b 0b 01b 81h

1 2 ... 95 96 97 98 99 100 101 102 103 104 105 ... 212 213

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Rainbow-electronics AT89C5122 Manual de usuario Pagina 100