CAT25020 Catalyst Semiconductor, CAT25020 Datasheet - Page 7

• Manufacturer Part Number: CAT25020
• Description: 2k Spi Serial Cmos Eeprom
• Manufacturer: Catalyst Semiconductor

Byte Write
Once the WEL bit is set, the user may execute a write
sequence, by sending a WRITE instruction, a 8-bit
address and data as shown in Figure 4. For the
CAT25040, bit 3 of the write instruction opcode
contains A8 address bit. Internal programming will
start after the low to high CS
internal write cycle, all commands, except for RDSR
(Read Status Register) will be ignored. The RDY
will indicate if the internal write cycle is in progress
(RDY
commands (RDY
Figure 4. Byte WRITE Timing
Notes:
Dashed Line = mode (1, 1) - - - - - -
* X = 0 for CAT25010, CAT25020. x = A8 for CAT25040
Figure 5. Page WRITE Timing
Notes:
Dashed Line = mode (1, 1) - - - - - -
* X = 0 for CAT25010, CAT25020. x = A8 for CAT25040
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
¯¯¯¯ high), or the the device is ready to accept
SCK
SCK
SO
SO
CS
CS
SI
SI
¯¯¯¯ low).
0
0
0
0
0
0
1
1
0
0
2
2
HIGH IMPEDANCE
0
0
¯¯ transition. During an
3
3
OPCODE
OPCODE
X*
X*
4
4
0
0
5
5
1
1
6
6
0
0
7
7
¯¯¯¯ bit
A 7
A
7
8
8
BYTE ADDRESS
BYTE ADDRESS
HIGH IMPEDANCE
13
13
7
14
Page Write
After
CAT25010/20/40, the host may continue sending
data, up to a total of 16 bytes, according to timing
shown in Figure 5. After each data byte, the lower
order address bits are automatically incremented,
while the higher order address bits (page address)
remain unchanged. If during this process the end of
page is exceeded, then loading will “roll over” to the
first byte in the page, thus possibly overwriting
previoualy loaded data. Following completion of the
write cycle, the CAT25010/20/40 is automatically
returned to the write disable state.
14
A
A 0
15
15 16-23 24-31
0
D7 D6 D5 D4 D3 D2 D1 D0
Data
Byte 1
16
sending
17
Data
Byte 2
DATA IN
18 19
CAT25010, CAT25020, CAT25040
Data
Byte 3
16+(N-1)x8-1..16+(N-1)x8 16+Nx8-1
DATA IN
the
20
first
7..1
21
Data Byte N
22
data
0
23
Doc. No. MD-1006 Rev. T
byte
to
the