LF3320
Horizontal Digital Image Filter
round register, the Filter B LF
DEVICES INCORPORATED
After the last data value is loaded, the
interface will expect a new address
value on the next clock cycle. After the
next address value is loaded, data
loading will begin again as previously
discussed. As long as data is loaded
into the interface, LDA must remain
LOW. After alldesired coefficient banks
and Configuration/ Controlregistersare
loaded with data, the LF InterfaceTM
must be disabled. This is done by
setting LDA HIGH on the clock cycle
after the clock cycle which latches the
last data value. It is important that the
LF InterfaceTM remain disabled when
not loading data into it.
The Configuration and Control
registers may be loaded with either the InterfaceTM will be allowed to load the
Filter A or BLF InterfacesTM
.
round register while the Filter A LF
InterfaceTM will not be allowed to load
the configuration register. However,
the Filter A LF InterfaceTM will
continue to function as if the write
occurred.
Since both LF InterfacesTM operate
independently of each other, both LF
InterfacesTM can load data into their
respective coefficient banks at the same
time. Or, one LF InterfaceTM can load
the Configuration/ Controlregisters
while the other loads it’s respective
coefficient banks. If both LF
TABLE 8. CFA/CFB11-9 DECODE
InterfacesTM are used to load a Configu- 11 10 9 DESCRIPTION
ration or Control register at the same
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
CoefficientBanks
time, the Filter B LF InterfaceTM will be
given priority over the Filter A LF
InterfaceTM. For example, if the Filter A
LF InterfaceTM attempts to load data
ConfigurationRegisters
Filter A Select Registers
Filter B Select Registers
Filter A Round Registers
Filter B Round Registers
FilterALimitRegisters
FilterBLimitRegisters
TheFilter Acoefficientbanksmayonlybe
loaded with theFilter ALF InterfaceTM and into a configuration register at the
theFilter Bcoefficientbanksmay only be
loaded with the Filter BLF InterfaceTM
same time that the Filter B LF
.
InterfaceTM attempts to load a Filter A
FIGURE 20. CONFIGURATION AND SELECT REGISTER LOADING SEQUENCE WITH PAUSE IMPLEMENTATION
CONFIGURATION REGISTER
SELECT REGISTER
CLK
W1
W2
PAUSEA/PAUSEB
LDA/LDB
CFA/CFB11-0
ADDR
1
DATA
1
ADDR
2
DATA1
W1: Configuration Register loaded with new data on this rising clock edge.
W2: Select Register loaded with new data on this rising clock edge.
FIGURE 21. ROUND REGISTER LOADING SEQUENCE WITH PAUSE IMPLEMENTATION
ROUND REGISTER
CLK
W1
PAUSEA/PAUSEB
LDA/LDB
CFA/CFB11-0
ADDR
1
DATA
1
DATA
2
DATA
3
DATA4
W1: Round Register loaded with new data on this rising clock edge.
Video Imaging Products
08/16/2000–LDS.3320-N
2-17
LOGIC [ LOGIC DEVICES INCORPORATED ]
