
4. Serial Control Data Input Setting Values
The input data consists of 16 bits (DI0 to DI15) of which the upper 8 bits (DI8 to DI15) are the control address
and the lower 8 bits (DI0 to DI7) are the input data.
Note: 1. The data in address bits DI12 to DI15 is ignored.
2. The value of the data sent to set the protection count must be one less than the desired protection count. In the default example shown above, the
block forward protection count will be 8 and the frame back protection count will be 2. When the value is set to 0, the protection count will be 1.
Since a protection count of 0 is meaningless the LSI ignores this value.
3. The initial threshold value is the initial value used when executing error correction at a variable threshold. There is no need to change this value
unless some special experiment is being performed. The threshold value can be set to a value from 9 to 15 according to a three-bit field. Therefore
a data value of 7 sets the threshold value to 15 and a data value of 1 sets the threshold value to 9.
4. The readout block number is transferred when the skip function is used.
5. Addresses other than those listed above (e.g. 0101) are special addresses unique to this LSI and are for test mode and other functions. These
addresses should not be used.
6. The default values are the values loaded into internal registers when a reset signal (RST) is received. These are recommended values and do not
require modification in normal operation. If the default values are used then there will be no need to implement control microprocessor software
that inputs control data.
No. 4870-6/14
LC72700E, LC72700G
Register
Address
Data
Default setting
DI11
DI10
DI9
DI8
Allowed error count
0
0
0
0
Upper 4 bits
Back allowed errors
2
Lower 4 bits
Forward allowed errors
2
Block error protection count
0
0
0
1
Upper 4 bits
Back protection count
1
Lower 4 bits
Forward protection count
7
Frame error protection count
0
0
1
0
Upper 4 bits
Back protection count
1
Lower 4 bits
Forward protection count
7
Error correction initial 
threshold value
0
0
1
1
Upper 5 bits
—
—
Lower 3 bits
Initial threshold value
7
Readout (output) block number
0
1
0
0
0 to 189 (8 bits)
0