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n Usage
Functional Overview
The basic sequence for reads and writes is the same: after the CE input goes high, the 4-bit mode is set, the 4-bit
address is specified, and then the data is read or written in 8-bit units.If the input of an 8-bit unit of data is not yet
complete when the CE input is set low, the 8-bit data that was being written when the CE input went low is ignored.
(Prior data is valid. Also, in these circumstances, the WF bit is set to "1", indicating that the write operation was not
completed normally.)Writes and reads are both LSB first.
[ Writes ]
1) After the CE input goes high, set the value of the first four write bits is to "3", indicating write mode, and then set
the address to be written in the next four bits.
2) The 8 bits of write data that follow are written to the address that was set; the address is then automatically
incremented, and the next 8 bits of data are written to the new address.
3) The automatic address incrementation is cyclic, with address 0 following address F.
C E
CLK
DATA
D0
D1
D2 D3
Write mode
CODE=3 (0011)
[ Reads ]
1) After the CE input goes high, set the value of the first four write bits to "C", indicating read mode, and then set the
address to be written in the next four bits.
2) The 8 bits of data that follow are read from the address that was set; the address is then automatically
incremented, and the next 8 bits of data are read from the new address.
3) The automatic address incrementation is cyclic, with address 0 following address F.
C E
CLK
DATA
D0 D1 D2
D3 D0
Set readout mode
CODE=C (1100)
If the mode setting code was set to a value other than "C" or "3", the subsequent data is ignored and the DATA pin
remains in the input state.
D0 D1
D2 D3
D0
D1
Write to address (N)
Write DATA to (N)
D2
D0
READ address (N)
D2 D3
D4
D5
D6
D7
D2
D4
D6
READ DATA
(address N)
Page-8
D0
D1
D2
D3
D4 D5
Write DATA
(to address N + 1)
D0
D2
D4
READ DATA
( address N + 1)
- - -
- - -
D6 D7
- - - -
- - -
D6
Aug.1998
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