TP3410J datasheet(23/32 Pages) NSC

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Functional Description (Continued)

FA0

This command may be used on a fully activated

line to force the transmit ‘‘act’’ bit e 0 to indicate

loss or denial of 2B a D transparency to the NT

(LT state J7) To revert back to sending ‘‘act’’ e 1

use the AC command (with BP2 e 1)

SEI

S-Interface Error Indication which should only be

used in an NT-1 when loss of received signal is

detected (ie INFO 0) This command forces the

upstream ‘‘act’’ bit (M41) e 0

Deactivation Confirmation This command may be

used as an alternative to PDN to power-down the

device in response to a DI indication It should not

be used prior to the DI indication

113 Activation Indication Register (READ ONLY)

Byte 2

7654

0000C4C3C2C1

Activation Indicators are coded the same as for the Activa-

tion Control Register In Microwire mode only at each acti-

vation status change the four significant bits in this register

are sent to the Interrupt stack If multiple interrupt conditions

should arise simultaneously this register has the highest

priority and will be read first

114 Activation Status Indicators

DPLSD When the TP3410 is deactivated either powered

up or powered down the Line Signal Detector

sets this indicator if it detects an incoming 10 kHz

wake-up tone If the device is powered down the

LSD pin is also pulled low In NT mode only this

code also functions as a Deactivation Pending in-

dicator when ‘‘dea’’e0 is validated

SYNC

In LT mode only this indicates when superframe

sync is detected and should be used to stop the

external default timer

Activation Pending which is used in NT mode to

indicate when superframe sync has been acquired

and the BCLK and FS outputs are synchronized to

the received line signal In LT mode the Line Sig-

nal Detector sets this indicator if it detects an in-

coming 10 kHz wake-up tone

This Activation Indication code indicates that the

loop is fully activated (‘‘act’’ e 1 has been re-

ceived) and the 2BaD channels are enabled for

data transfer In LT mode however if Breakpoint

2 is enabled via CR2 it is necessary to respond

to AI with an AC command This will cause the

device to set ‘‘act’’e1 in the transmit frame and

open the 2BaD channels for data transfer

Loss of frame synchronization will set this Error

Indicator and inhibit the 2BaD channel data If a

received line signal can still be detected the de-

vice will attempt to recover synchronization for up

to 480 ms if this fails it will enter the RESET state

and generate a DI The EI indication is also gener-

ated on an activated line if the received ‘‘act’’ bit

changes from 1 to 0 indicating loss of tranparen-

cy at the far-end

The Deactivated Indication which confirms that

the loop has been deactivated by means of a De-

activate Request at the LT and has entered the

RESET state DI is effective in GCI mode only

TIM

In GCI mode only TIM is an acknowledgment

when the device is in the power-down state and

receives a PUP command

115 Cold Start and Warm Start

When power is first applied to the device the first AR com-

mand will always initiate a cold-start sequence which may

take up to 15 seconds for complete activation If the device

is subsequently deactivated using the correct procedure

and provided power is maintained uninterrupted in either the

power-up or power-down state the next AR instruction au-

tomatically sequences through the warm-start procedure

which normally achieves complete loop activation within

300 ms

The device includes the specified timers of 15s 480 ms and

40 ms at the appropriate phases of the activation and deac-

tivation sequences For applications requiring a default time-

out other than 15s the internal timer can be disabled to

allow an external timer to be used

116 LT Mode ActivationDeactivation

If activation is initiated by the downstream (NT mode) end

with the device either powered up or down an AP Interrupt

condition will be generated on detection of the 10 kHz

‘‘wake-up’’ tone The Activation Indication Register will

show this condition and if the device is powered down the

LSD pin will be pulled low

Prior to initiating activation all registers must be pro-

grammed appropriately and the device must then be pow-

ered up The use of the commands and status indicators is

the same whether activation is initiated locally or from the

remote end An AR command is required to enable the de-

vice to proceed with the activation sequence An internal

15s default timer is also started (in North America the timer

value should be 15 seconds if a single loop section is being

activated) Please see TP3410 User’s Manual for additional

information on activation and deactivation

The sequence continues automatically until superframe syn-

chronization is acquired on the SN3 signal received from the

NT At this point the ‘‘act’’ bit is set e 1 in the downstream

direction and the AI Interrupt is generated in the Activation

Indication Register The loop is then fully activated with all

channels in the data stream available for use

If activation is not successfully completed before expiry of

the 15s timer the device generates an EI followed by a DI

fault indication and ensures that the Activation Sequencer

returns to the Full Reset state (J10 to J1) prior to any re-

attempt to activate

For additional control over the activation sequence a break-

point state may be enabled at the LT BP2 will halt the

sequence when the loop is fully synchronized receiving

SN3 but the ‘‘act’’ bit is held e 0 this state prevents the

ST Interface from becoming fully activated (the NT1 will

maintain INFO2 towards the TEs) An AC command will re-

lease this state allowing activation to be completed The

BP2 bit in Register CR2 controls the enabling of this break-

point

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