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AS8202B

Datasheet - Detailed Descr i p ti on

7.6 Test Interface

The Test Interface supports the manufacturing test and characterization of the chip. In the application environment test pins have to be

connected as following:



STEST, FTEST, FIDIS: connect to VSS



TTEST: connect to VDD

7.7 LED Signals

The LED port consists of three pins. Via the MEDL each of these pins can be independently configured for any of the three modes of operation.

At Power-Up and after Reset the LED port is inactive and only weak pull-down resistors are connected. After the controller is switched on by the

host and when it is processing its initialization, the LED port is initialized to the selected mode of operation.

Each LED pin can be configured to be either a push/pull driver (drives both LOW and HIGH) or to be only an open-drain output (drives only

LOW).

RxD[0]

in

RxD0

Receive data channel 0

TxD[1]

out

TxD0

Transmit data channel 1

CTS[1]

out

TxEN

Transmit enable channel 1

TxCLK[1]

in

TxCLK

Transmit clock channel 1

RXER[1]

in

RXER

Receive error channel 1

RXCLK[1]

in

RXCLK

Receive clock channel 1

RxDV[1]

in

RxDV

Receive data valid channel 1

RxD[1]

in

RxD0

Receive data channel 1

Caution: Any other connection of these pins may cause permanent damage to the device and to additional devices of the application.

Table 12. LED Signals

Pin Name

Protocol Mode

Timing Mode

Bus Guardian Mode

LED2

RPV

1

or

Protocol activity

7

1. RPV is Remote Pin Voting. RPV is a network-wide agreed signal used typically for agreed power-up or power-down of the application's

external drivers.

Time Overflow

2

2. Time Overflow is active for one clock cycle at the event of an overflow of the internal 16-bit time counter. Time Tick is active for one clock

cycle when the internal time is counted up. Time Overflow and Time Tick can be used to externally clone the internal time control unit

(TCU). With this information the application can precisely sample and trigger events, for example.

Action Time

3

3. Action Time signals the start of a bus access cycle.

LED1

Sync Valid

4

4. The controller sets this output when cluster synchronization is achieved (after integration from the LISTEN state, after acknowledge in

the COLDSTART state).

Time Tick

2

BDE1

5

5. BDE0 and BDE1 show the Bus Guardian's activity, '1' signals an activated transmitter gate on the respective channel.

LED0

Protocol activity

6

or RPV

7

6. Protocol activity is typically connected to an optical LED. The flashing frequency and rhythm give a simple view to the internal TTP pro-

tocol state.

7. LED2's RPV mode and LED0's Protocol activity mode can be swapped with a MEDL parameter.

Microtick

8

8. Microtick is the internal main clock signal.

BDE0

5

Table 11. Synchronous Bus Interface Connections

Pin Name

Mode

Connect to PHY

Note