SM8578BV
USAGE NOTES
Data Read/Write
I
I
I
I
For both writing and reading data, the first 4 bits after CE goes HIGH are mode select bits, the next 4 bits
assign the address, and subsequent bits are read/write data in 8-bit units.
When writing data, the data must be input in 8-bit units.
If CE goes LOW before an 8-bit unit data word is input, the 8-bit data being written when CE goes LOW
will not be written correctly.
Write data and read data are in LSB-first format.
[Write mode]
1) If the first 4 bits after CE goes HIGH have value “3”, write mode is selected. The next 4 bits determine the
write address.
2) The next 8-bit data unit is written to the write address, and subsequent 8-bit data units are written to consec-
utive locations addressed using an automatic address increment function.
3) The address automatic increment function is cyclical, with address 0 following after address F.
CE
CLK
DATA
D0 D1 D2 D3 D0 D1 D2 D3 D0 D1 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3 D4 D5 D6 D7
Write mode
select code (3
H
)
Adress
select (N)
Data write (adress N)
Data write (adress N+1)
[Read mode]
1) If the first 4 bits after CE goes HIGH have value “C”, read mode is selected. The next 4 bits determine the
read address.
2) The next 8-bit data unit is read from the read address, and subsequent 8-bit data units are read from consec-
utive locations addressed using an automatic address increment function.
3) The address automatic increment function is cyclical, with address 0 following after address F.
CE
CLK
DATA
D0 D1 D2 D3 D0 D1 D2 D3
D0 D1 D2 D3 D4 D5 D6 D7 D0 D1 D2 D3 D4 D5 D6 D7
Read mode
select code (C
H
)
Adress
select (N)
Data read (adress N)
Data read (adress N+1)
From the point DATA is in output mode.
Note. If the mode set code is neither “C” nor “3”, all subsequent data is ignored and the DATA pin input state is maintained.
NIPPON PRECISION CIRCUITS INC.—13
NPC [ NIPPON PRECISION CIRCUITS INC ]
