cy24c01 Cypress Semiconductor Corporation., cy24c01 Datasheet - Page 5

• Manufacturer Part Number: cy24c01
• Description: 1 Kbit, 2 Kbit, 4 Kbit, 8 Kbit, And 16 Kbit X8 Two Wire I2c Serial Eeprom
• Manufacturer: Cypress Semiconductor Corporation.

Read Operations
Read operations are initiated in the same way as write opera-
tions except that the read or write select bit in the device address
word is set to one. There are three read operations: current
address read, random address read, and sequential read.
Current Address Read
The internal data word address counter maintains the last
address accessed during the last read or write operation, incre-
mented by one. This address stays valid between operations as
long as the chip power is maintained. The address roll over
during read and byte write is from the last byte of the last memory
page to the first byte of the first page. The address roll over
during write is from the last byte of the current page to the first
byte of the same page. After the device address with the read or
write select bit set to one is clocked in and acknowledged by the
EEPROM, the current address data word is serially clocked out.
The microcontroller does not respond with an input zero but
generates a stop condition (see
Table 3. Device Addressing
Table 4. Operating Modes
Notes
Document #: 001-15632 Rev. *C
Current Address Read
Random Address Read
Sequential Read
Byte Write
Page Write
1. P2, P1, P0 are used for memory page addressing.
2. A2, A1 and A0 are compared against the respective external pins on the memory device.
3. The MSB b7 is sent first.
Density
1K/2K
16K
4K
8K
Mode
b7
1
1
1
1
Device Type Identifier
[1,2,3]
Figure 6
b6
R/W Bit
0
0
0
0
1
0
1
1
0
0
on page 6).
b5
1
1
1
1
WP
X
X
X
X
0
0
b4
0
0
0
0
Bytes
<16
>1
1
1
1
Random Read
A random read needs a ‘dummy’ byte write sequence to load in
the data word address. After the device address word and data
word address are clocked in and acknowledged by the
EEPROM, the microcontroller must generate another start
condition. The microcontroller initiates a current address read by
sending a device address with the read or write select bit high.
The EEPROM acknowledges the device address and serially
clocks out the data word. The microcontroller does not respond
with a zero but generates a stop condition as shown in
Figure 7
Sequential Read
Sequential reads are initiated by either a current address read or
a random address read. After the microcontroller receives a data
word, it responds with an acknowledgement. As long as the
EEPROM receives an acknowledgement, it continues to
increment the data word address and serially clocks out
sequential data words. When the address memory limit is
reached, the data word address rolls over and the sequential
read continues. The sequential read operation is terminated
when the microcontroller does not respond with a zero but
generates a stop condition (see
Start, Device Select, R/W = 1
Start, Device Select, R/W = 0, Address
reStart, Device Select, R/W = 1
Similar to Current or Random Address Read
Start, Device Select, R/W = 0
Start, Device Select, R/W = 0
A2
A2
A2
P2
b3
Initial Sequence
on page 6.
Chip Enable Address
A1
b2
A1
P1
P1
CY24C01/02/04/08/16
Figure 8
b1
A0
P0
P0
P0
on page 7).
Page 5 of 16
R/W
R/W
R/W
R/W
b0
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