TDA8031 Datasheet, PDF (44/57 Pages) NXP Semiconductors – USB smart card reader (OTP or ROM)

Philips Semiconductors
USB smart card reader (OTP or ROM)
Product specification
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 kΩ pull-up resistor is integrated between pins D+
and V_DDD 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 V_DDD 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.
2003 Jul 04
44