TDA8031 datasheet(44/57 Pages) PHILIPS

44 / 57 page

2003 Jul 04

Philips Semiconductors

Product speciﬁcation

USB smart card reader (OTP or ROM)

TDA8030; TDA8031

8.5.8

ANALOG INTERFACE

The transceiver interfaces directly to the USB cables

through termination resistors. They are able to transmit

and receive serial data at full speed (12 Mbits/s).

A 1.5 k

Ω pull-up resistor is integrated between pins D+

and VDDD and is connected by software by the

microcontroller; in case a

±5% resistor is preferred, it can

be externally connected between pins DELATT and D+

(DELATT is also controlled by software and is floating

when OFF, or connected to VDDD when ON).

8.5.9

SUSPEND MODE

When the USB interface enters Suspend mode, the

software should set the microcontroller in power-down

mode in order to respect the suspend current condition.

The following sequence should be executed:

1. When the device enters the Suspend mode, it

generates an interrupt on pin INT1

2. The software should set USB_INT_MASK to logic 1

3. Then it should wait until CLK_EN_N is HIGH before

entering power-down mode.

When the device detects an activity on the bus, it resets

CLK_EN_N to logic 0 and generates an interrupt on pin

INT1. When leaving the Suspend mode, the following

sequence should be executed:

1. The software should read the DEVICE_STATUS to

enable the interrupt to be cleared

2. Reset USB_INT_MASK to logic 0.

TDA8031 Datasheet(PDF) 44 Page - NXP Semiconductors