Philips Semiconductors

ISP1104

Advanced USB transceiver

Product data

Rev. 02 — 14 October 2003

5 of 19

9397 750 11229

© Koninklijke Philips Electronics N.V. 2003. All rights reserved.

7.

Functional description

7.1 Function selection

[1]

Signal levels on pins D

+ and D− are determined by other USB devices and external pull-up or

pull-down resistors.

[2]

In the suspend mode (pin SUSPND = HIGH), the differential receiver is inactive and the output RCV is

always LOW. Out-of-suspend (K) signalling is detected via the single-ended receivers VP and VM.

7.2 Operating functions

[1]

[2]

RCV* denotes the signal level on output RCV just before the SE0 state occurs. This level is stable

during the SE0 period.

Table 3:

Function table

SUSPND OE

D

+ and D−

RCV

VP/VM

Function

L

L

driving/

receiving

active

active

normal driving

(differential receiver active)

L

H

receiving[1]

active

active

receiving

H

L

driving

inactive[2]

active

driving during ‘suspend’

(differential receiver inactive)

H

H

high-Z[1]

inactive[2]

active

low-power state

Table 4:

Driving function using single-ended input data interface (pin OE = L and

pin MODE = L)

FSE0

VO

Data

L

L

differential logic 0

L

H

differential logic 1

H

L

SE0

H

H

SE0

Table 5:

Driving function using differential input data interface (pin OE = L and

pin MODE = H)

VMO

VPO

Data

L

L

SE0

L

H

differential logic 1

H

L

differential logic 0

H

H

illegal state

Table 6:

Receiving function (pin OE=H)

D

+ and D−

RCV

VP[1]

VM[1]

differential logic 0

L

L

H

differential logic 1

H

H

L

SE0

RCV*[2]

LL