24aa174 Microchip Technology Inc., 24aa174 Datasheet - Page 6

• Manufacturer Part Number: 24aa174
• Description: 16k 1.8v Cascadable I 2c? Serial Eeprom With Otp Security Page
• Manufacturer: Microchip Technology Inc.

24AA174
FIGURE 4-1:
FIGURE 4-2:
5.0
Since the device will not acknowledge during a write
cycle, this can be used to determine when the cycle is
complete (this feature can be used to maximize bus
throughput). Once the stop condition for a write com-
mand has been issued from the master, the device ini-
tiates the internally timed write cycle. ACK polling can
be initiated immediately. This involves the master send-
ing a start condition followed by the control byte for a
write command (R/W = 0). If the device is still busy with
the write cycle, then no ACK will be returned. If the
cycle is complete, then the device will return the ACK
and the master can then proceed with the next read or
write command. See Figure 5-1 for flow diagram.
DS21102G-page 6
BUS ACTIVITY:
MASTER
BUS ACTIVITY:
SDA LINE
ACKNOWLEDGE POLLING
BUS ACTIVITY:
MASTER
SDA LINE
BUS ACTIVITY:
BYTE WRITE
PAGE WRITE
S
A
R
T
T
S
A2
CONTROL
A1 A0 B2 B1
BYTE
S
A
R
T
T
B0
S
1 A2
A
C
K
CONTROL
A1 A0 B2 B1
BYTE
ADDRESS (n)
WORD
B0
A
C
K
C
A
K
ADDRESS
WORD
DATA n
FIGURE 5-1:
6.0
The 24AA174 can be used as a serial ROM when the
WP pin is connected to V
ited and the entire memory will be write-protected.
WRITE PROTECTION
C
A
K
A
C
K
Initiate Write Cycle
Send Control Byte
Write Command
with R/W = 0
Acknowledge
DATA n + 1
Condition to
Send Stop
(ACK = 0)?
Did Device
ACKNOWLEDGE POLLING
FLOW
Send Start
DATA
Operation
Send
Next
CC
YES
2004 Microchip Technology Inc.
. Programming will be inhib-
A
C
K
A
C
K
S
T
O
P
P
DATA n + 15
NO
A
C
K
S
T
O
P
P