1998 Oct 06

24

Philips Semiconductors

Preliminary specification

Universal Serial Bus (USB)

Digital-to-Analog Converter (DAC)

UDA1321

Table 7

No digital I/O communication

Notes

1. The input pins must have a pull-up resistor.

2. Connect/disconnect: holds the USB ‘disconnected’ as long as the initialization is not finished.

3. Alarm mute: input to switch the sound off; specially used if the USB host program does not respond to the control.This

pin acts directly on the sound and passes the mute to the USB host.

4. Standby is switched on (output becomes LOW) after a programmable time if mute is active (see Byte 18 of Table 6).

5. Mute is switched on (output becomes LOW) after a programmable time if the isochronous data flow is interrupted

(see Byte 17 of Table 6).

6. For selection between HID/LED application see configuration map byte 11 (output is active HIGH).

Table 8

4-pins digital I/O communication

Notes

1. Connect/disconnect: holds the USB ‘disconnected’ as long as the initialization is not finished.

2. Alarm mute: input to switch the sound off; specially used if the USB host program does not respond to the control.

This pin acts directly on the sound and passes the mute to the USB host.

PIN

INPUT/OUTPUT

FUNCTION 1

FUNCTION 2

GP5

output; not programmable; note 2

connect/disconnect

connect/disconnect

GP4

inputs; programmable; note 1

alarm mute; note 3

HID input 3

GP3

HID input 2

HID input 2

GP0

HID input 1

HID input 1

GP2

outputs; programmable

standby; note 4

HID/LED output 2; note 6

GP1

mute; note 5

HID/LED output 1; note 6

PIN

INPUT/OUTPUT

FUNCTION 1

FUNCTION 2

GP5

output; not programmable; note 1

connect/disconnect

connect/disconnect

GP4

digital I/O-bus

BCKO

BCKO

GP3

WSO

WSO

GP2

DO

DO

GP1

DI

DI

GP0

input; programmable

HID input 1

alarm mute; note 2