The 93C46 provides 1024 bits of serial electrically-erasable programmable read-only memory (EEPROM) organized as 64 words of 16 bits each. The device is opti-mized for use in many industrial and commercial applications where low-power and low-voltage operation are essential. The 93C46 is available in space-saving 8-lead PDIP, 8-lead JEDEC SOIC, and 8-lead TSSOP packages.
The 93C46 is enabled through the Chip Select pin (CS) and accessed via a three-wire serial interface consisting of Data Input (DI), Data Output (DO), and Shift Clock (SK). Upon receiving a Read instruction at DI, the address is decoded and the data is clocked out serially on the data output DO pin. The write cycle is completely self-timed and no separate erase cycle is required before write. The write cycle is only enabled when the part is in the erase/write enable state. When CS is brought high following the initiation of a write cycle, the DO pin outputs the ready/busy status of the part.
CS: Chip Select
SK: Serial Data Clock
DI: Serial Data Input
DO: Serial Data Output
GND: Ground
VCC: Power Supply
NC: No Connect
Instruction Set for the AT93C46E:
| Instruction | SB | Op Code | Address | Comments |
| READ | 1 | 10 | A5 − A0 | Reads data stored in memory, at specified address |
| EWEN | 1 | 00 | 11XXXX | Write enable must precede all programming modes |
| ERASE | 1 | 11 | A5 − A0 | Erase memory location An − A0 |
| WRITE | 1 | 01 | A5 − A0 | Writes memory location An − A0 |
| ERAL | 1 | 00 | 10XXXX | Erases all memory locations. Valid only at VCC = 4.5V to 5.5V |
| WRAL | 1 | 00 | 01XXXX | Writes all memory locations. Valid only at VCC = 4.5V to 5.5V |
| EWDS | 1 | 00 | 00XXXX | Disables all programming instructions |
Program Function
The experiment illustrates the I2C communication between MCU and 24C01 EEPROM. Data 0×55 and 0xAA are written to EEPROM at memory address 0×02 and 0×03. The data read from EEPROM will be displayed on LED display. By default, the address to be read is 0×02, user can change the address.
Toggle on the function select to ‘93C**’ before this experiment.