No. 6871-8/29

LC72714W

This IC detects the BIC characteristic inflection points which occur at four places in a single frame, and increments or

decrements a protection counter depending on whether or not they match the IC internal frame synchronization timing

counter.

As is the case with the block synchronization error protection value, applications must set these to values one less than

the desired protection count. The default values are 8 for the frame synchronization forward protection count and 2 for

the back protection count.

Frame Synchronization: Error Protection Count

Address

Register

R/W

Initial value

BIT7

BIT6

BIT5

BIT4

BIT3

BIT2

BIT1

BIT0

03H

SYNCF

W

17H

Back protection

(LSB)

Forward protection

(LSB)

*: BIT0 and BIT1 are unused.

• VEC_HALT

0: Vertical correction and the second horizontal correction processing are performed. (default)

1: Vertical correction and the second horizontal correction processing are not performed.

All IC operations related to vertical correction and the second horizontal correction are stopped by setting this flag.

Note that in data output, only data to which the first horizontal correction has been applied will be output.

• EC_STOP

0: All functions operate. (default)

1: Only the MSK detection circuit and the synchronization regeneration circuit operate.

This flag stops all operations relating to error correction (including RAM access), data output, and other operations.

While all IC operations are stopped in standby mode, MSK demodulation, the synchronization circuit, the serial data

input circuit, and the layer 4 CRC circuit continue to operate in this mode.

• SYNC_RST

0: (default)

1: Resets just the synchronization regeneration circuit.

Clears the synchronization status and the synchronization protection status in the synchronization circuit block, and

sets the circuit to the unsynchronized state. This allows the circuit to quickly pull in to frame synchronization when

the frame synchronization is incorrect for the new reception data following tuning, when the radio has been tuned to

a new station. While this flag is used for synchronization related sections of the system, it does not initialize the

registers that set the number of allowable BIC errors, the block synchronization forward and back protection counts,

and the frame synchronization forward and back protection counts. Also note that during a synchronization block

reset, the INT signal is not output and the DO pin outputs a high level (high-impedance).

This flag is not automatically reset to 0. Applications must send a 0 value after setting this flag.

Control Register 1

Address

Register

R/W

Initial value

BIT7

BIT6

BIT5

BIT4

BIT3

BIT2

BIT1

BIT0

04H

CTL1

W

00H

CRC4_RST

DO_MOVE

INT_MOVE SYNC_RST

EC_STOP

VEC_HALT

*

*

• INT_MOVE

0: Data is only output when error correction has completed, layer 2 CRC has completed, and the data was received with

the circuit synchronized. (default)

1: All data is output. (Operation is identical to that of the LC72700E.)

In the default state, this IC only outputs data that has been fully error corrected and that was received in both block

and frame synchronization. (This also includes the layer 2 CRC check.)

To acquire all data as provided by the LC72700, applications must set both this flag and the VEC_OUT (BIT2) flag

in control register 2 as described below.

• DO_MOVE (Valid only when SP is high.)

0: The high state (high impedance) is held at all times other than when data is being output. (default)

1: Operate identically to the LC72700 when changes are linked to the INT signal, i.e. when both INT_MOVE and

VEC_OUT are set to 1.

• CRC4_RST

0: (default)

1:Reset the layer 4 CRC detection circuit.

This flag is not automatically reset to 0. Applications must send a 0 value after setting this flag.