at25020b-wwu11l ATMEL Corporation, at25020b-wwu11l Datasheet - Page 5

• Manufacturer Part Number: at25020b-wwu11l
• Description: Spi Serial Eeprom
• Manufacturer: ATMEL Corporation

8707B–SEEPR–3/10
2.
Table 1-3.
Applicable over recommended operating range from T
CL = 1 TTL Gate and 30 pF (unless otherwise noted)
Note:
Serial Interface Description
MASTER: The device that generates the serial clock.
SLAVE: Because the serial clock pin (SCK) is always an input, the AT25010B/020B/040B always operates as a
slave.
TRANSMITTER/RECEIVER: The AT25010B/020B/040B has separate pins designated for data transmission (SO)
and reception (SI).
MSB: The Most Significant Bit (MSB) is the first bit transmitted and received.
SERIAL OP-CODE: After the device is selected with CS going low, the first byte will be received. This byte con-
tains the op-code that defines the operations to be performed. The op-code also contains address bit A8 in both
the read and write instructions.
INVALID OP-CODE: If an invalid op-code is received, no data will be shifted into the AT25010B/020B/040B, and
the serial output pin (SO) will remain in a high impedance state until the falling edge of CS is detected again. This
will reinitialize the serial communication.
CHIP SELECT: The AT25010B/020B/040B is selected when the CS pin is low. When the device is not selected,
data will not be accepted via the SI pin, and the SO pin will remain in a high impedance state.
HOLD: The HOLD pin is used in conjunction with the CS pin to select the AT25010B/020B/040B. When the device
is selected and a serial sequence is underway, HOLD can be used to pause the serial communication with the
master device without resetting the serial sequence. To pause, the HOLD pin must be brought low while the SCK
pin is low. To resume serial communication, the HOLD pin is brought high while the SCK pin is low (SCK may still
toggle during HOLD). Inputs to the SI pin will be ignored while the SO pin is in the high impedance state.
WRITE PROTECT: The write protect pin (WP) will allow normal read/write operations when held high. When the
WP pin is brought low, all write operations are inhibited.
WP going low while CS is still low will interrupt a write to the AT25010B/020B/040B. If the internal write cycle has
already been initiated, WP going low will have no effect on any write operation.
Symbol
t
t
t
Endurance
HZ
DIS
WC
1. This parameter is characterized and is not 100% tested.
(1)
AC Characteristics (Continued)
Parameter
Hold to Output High Z
Output Disable Time
Write Cycle Time
5.0V, 25C, Page Mode
AT25010B/020B/040B [Preliminary]
AI
4.5  5.5
2.5  5.5
1.8 5.5
4.5 5.5
2.5  5.5
1.8 5.5
4.5  5.5
2.5  5.5
1.8 5.5
Voltage
= 40 to +85°C, V
Min
1M
CC
= As Specified,
Max
100
100
25
50
25
50
5
5
5
Write Cycles
Units
ms
ns
ns
5