ASAHI KASEI
[AK93C45A/55A/65A/75A]
General Description
The AK93C45A/55A/65A/75A is a 1024/2048/4096/8192-bit serial CMOS EEPROM divided into
64/128/256/512 registers of 16 bits each.
The AK93C45A/55A/65A/75A has 4 instructions such as READ, WRITE, EWEN and EWDS. Those
instructions control the AK93C45A/55A/65A/75A.
The AK93C45A/55A/65A/75A can operate full function under wide operating voltage range from 1.8V to 5.5V.
The charge up circuit is integrated for high voltage generation that is used for write operation.
A serial interface of AK93C45A/55A/65A/75A, consisting of chip select (CS), serial clock (SK), data-in (DI)
and data-out (DO), can easily be controlled by popular microcontrollers or standard microprocessors.
AK93C45A/55A/65A/75A takes in the write data from data input pin (DI) to a register synchronously with rising
edge of input pulse of serial clock pin (SK). And at read operation, AK93C45A/55A/65A/75A takes out the
read data from a register to data output pin (DO) synchronously with rising edge of SK.
The DO pin is usually in high impedance state. The DO pin outputs "L" or "H" in case of data output or Busy/Ready
signal output.
Software and Hardware controlled write protection
When Vcc is applied to the part, the part automatically powers up in the ERASE/WRITE Disable state. In the
ERASE/WRITE disable state, execution of WRITE instruction is disabled. Before WRITE instruction is
executed, EWEN instruction must be executed. The ERASE/WRITE enable state continues until EWDS
instruction is executed or Vcc is removed from the part.
Execution of a read instruction is independent of both EWEN and EWDS instructions.
The PE is internally pulled up to VCC. If the PE is left unconnected, the part will accept WRITE, EWEN and
EWDS instructions. AK93C55A/65A
Busy/Ready status signal
After a write instruction, the DO output serves as a Busy/Ready status indicator. After the falling edge of the
CS initiates the self-timed programming cycle, the DO indicates the Busy/Ready status of the chip if the CS is
brought high after a minimum of 250ns (Tcs). DO=logical "0" indicates that programming is still in progress.
DO=logical "1" indicates that the register at the address specified in the instruction has been written with the
new data pattern contained in the instruction and the part is ready for a next instruction.
The Busy/Ready status indicator is only valid when CS is active (high). When CS is low, the DO output goes
into a high impedance state.
The Busy/Ready signal outputs until a start bit (Logic"1") of the next instruction is given to the part.
DAM01E-01
1999/10
- 2 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
