AT93C56B-MAHM-T Atmel, AT93C56B-MAHM-T Datasheet - Page 5

• Manufacturer Part Number: AT93C56B-MAHM-T
• Description: EEPROM 2K (256x8/128x16) 3-WIRE NiPdAu, 1.7V
• Manufacturer: Atmel

Specifications of AT93C56B-MAHM-T

• Rohs: yes
• Factory Pack Quantity: 5000

8735A–SEEPR–1/11
Table 1-4.
Note:
2.
Instruction
READ
EWEN
ERASE
WRITE
ERAL
WRAL
EWDS
The Xs in the address field represent “don’t care” values, and must be clocked
Functional Description
The Atmel
operation is controlled by seven instructions issued by the host processor. A valid instruction starts with a rising edge of
CS, and consists of a start bit (logic one) followed by the appropriate op code and the desired memory address location.
READ (READ): The read (READ) instruction contains the address code for the memory location to be read. After the
instruction and address are decoded, data from the selected memory location is available at the serial output pin, DO.
Output data changes are synchronized with the rising edges ofthe serial clock, SK. It should be noted that a dummy bit
(logic zero) precedes the 8- or 16-bit data output string. The AT93C56B/66B supports sequential read operations. The
device will automatically increment the internal address pointer and clock out the next memory location as long as chip
select (CS) is held high. In this case, the dummy bit (logic zero) will not be clocked out between memory locations, thus
allowing for a continuous stream of data to be read.
ERASE/WRITE ENABLE (EWEN): To assure data integrity, the part automatically goes into the erase/write disable
(EWDS) state when power is first applied. An erase/write enable (EWEN) instruction must be executed first before any
programming instructions can be carried out. Please note that once in the EWEN state, programming remains enabled until
an EWDS instruction is executed or V
ERASE (ERASE): The erase (ERASE) instruction programs all bits in the specified memory location to the logical-one
state. The self-timed erase cycle starts once the ERASE instruction and address are decoded. The DO pin outputs the
ready/busy status of the part if CS is brought high after being kept low for a minimum of 250ns (t
indicates that the selected memory location has been erased and the part is ready for another instruction.
WRITE (WRITE): The Write (WRITE) instruction contains the 8- or 16-bits of data to be written into the specified memory
location. The self-timed programming cycle, t
pin outputs the ready/busy status of the part if CS is brought high after being kept low for a minimum of 250ns (t
logic zero at DO indicates that programming is still in progress. A logic one indicates that the memory location at the
specified address has been written with the data pattern contained in the instruction and the part is ready for further
instructions. A ready/busy status cannot be obtained if CS is brought high after the end of the self-timed programming
cycle, t
ERASE ALL (ERAL): The erase all (ERAL) instruction programs every bit in the memory array to the logic one state, and
is primarily used for testing purposes. The DO pin outputs the ready/busy status of the part if CS is brought high after being
kept low for a minimum of 250ns (t
Instruction Set for the Atmel AT93C56B and Atmel AT93C66B
SB
1
1
1
1
1
1
1
WP
.
®
Code
Op
AT93C56B/66B is accessed via a simple and versatile three-wire serial communication interface. Device
10
00
11
01
00
00
00
11XXXXXXX
10XXXXXXX
01XXXXXXX
00XXXXXXX
A
A
A
8
8
8
x 8
– A
– A
– A
0
0
0
Address
11XXXXXX
10XXXXXX
01XXXXXX
00XXXXXX
A
A
A
CS
x 16
7
7
7
CC
). The ERAL instruction is valid only at V
– A
– A
– A
power is removed from the part.
0
0
0
WP
, starts after the last bit of data is received at serial data input pin DI. The DO
D
D
7
7
x 8
– D
– D
0
0
Data
D
D
15
15
x 16
– D
– D
0
0
Comments
Reads data stored in memory at specified address
Write enable must precede all programming modes
Erases memory location A
Writes memory location A
Erases all memory locations. Valid only at
Writes all memory locations. Valid only at
Disables all programming instructions
V
V
CC
CC
CC
= 4.5V to 5.5V
= 5.0V ±10% and disable register cleared
= 5.0V 10%.
Atmel AT93C56B/66B
CS
n
n
). A logic one at pin DO
– A
– A
0
0
CS
). A
5