Details

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BUY AT29C020-12PC https://www.utsource.net/itm/p/427895.html
2-Megabit 256K x 8 5-volt Only CMOS Flash Memory

Below is the parameter table and instructions for the AT29C020-12PC, a 256K x 8 CMOS Electrically Erasable and Programmable Read-Only Memory (EEPROM) device.

Parameter Table

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
Supply Voltage	Vcc	4.5	5.0	5.5	V	Operating
Standby Current	Icc	-	10	20	μA	Vcc = 5V, TA = 25°C
Active Current	Icc	-	25	35	mA	Vcc = 5V, TA = 25°C, Reading
Write Current	Icc	-	10	15	mA	Vcc = 5V, TA = 25°C, Writing
Output High Voltage	VOH	2.4	-	Vcc - 0.4	V	IO = -1mA, Vcc = 5V, TA = 25°C
Output Low Voltage	VOL	-	-	0.4	V	IO = 1mA, Vcc = 5V, TA = 25°C
Input Low Voltage	VIL	-	-	0.8	V	Vcc = 5V, TA = 25°C
Input High Voltage	VIH	2.0	-	-	V	Vcc = 5V, TA = 25°C
Address Setup Time	tAS	0	-	10	ns	Vcc = 5V, TA = 25°C
Address Hold Time	tAH	0	-	10	ns	Vcc = 5V, TA = 25°C
Data Setup Time	tDS	0	-	10	ns	Vcc = 5V, TA = 25°C
Data Hold Time	tDH	0	-	10	ns	Vcc = 5V, TA = 25°C
Access Time	tAA	70	-	90	ns	Vcc = 5V, TA = 25°C
Write Cycle Time	tWC	8	-	12	ms	Vcc = 5V, TA = 25°C
Erase/Program Cycle Endurance	-	-	100,000	-	Cycles	-
Data Retention	-	10	-	-	Years	-

Instructions

1. Power Supply:

   • Ensure that the supply voltage (Vcc) is within the range of 4.5V to 5.5V.
   • The device should be powered with a stable 5V supply for optimal performance.

2. Addressing:

   • The device has 18 address lines (A0-A17) to access the 256K x 8 memory space.
   • Address setup time (tAS) and hold time (tAH) must be observed to ensure reliable data access.

3. Data Input/Output:

   • Data input/output is performed through the 8 data lines (D0-D7).
   • Data setup time (tDS) and hold time (tDH) must be adhered to for correct data transfer.

4. Control Signals:

   • Chip Select (CS): Active low. When CS is low, the chip is selected.
   • Output Enable (OE): Active low. When OE is low, the output buffers are enabled.
   • Write Enable (WE): Active low. When WE is low, a write operation is initiated.
   • Write Protect (WP): Active high. When WP is high, write operations are inhibited.

5. Read Operation:

   • Set CS and OE low.
   • Apply the desired address to the address lines.
   • Wait for the access time (tAA) before reading the data from the data lines.

6. Write Operation:

   • Set CS and WE low.
   • Apply the desired address to the address lines.
   • Apply the data to be written to the data lines.
   • Wait for the write cycle time (tWC) before performing another write or read operation.

7. Erase Operation:

   • The entire chip can be erased using a special sequence of commands or by applying a high voltage to the chip.
   • Refer to the datasheet for specific erase sequences and conditions.

8. Write Protect:

   • To prevent accidental writes, set the WP pin high.

9. Endurance and Data Retention:

   • The device can endure up to 100,000 erase/write cycles.
   • Data retention is guaranteed for at least 10 years under normal operating conditions.

10. Handling:

    • Handle the device with care to avoid static discharge, which can damage the internal circuitry.
    • Use proper anti-static precautions when handling the device.

For more detailed information, refer to the official datasheet provided by the manufacturer.

(For reference only)