Timing Diagrams

Note:

condition of sequential command.

HT24LC02A

Rev. 1.00

6

January 29, 2013

A random read requires a dummy byte write sequence

to load in the data word address which is then clocked

in and acknowledged by the EEPROM. The

microcontroller must then generate another start con-

dition. The microcontroller now initiates a current ad-

dress read by sending a device address with the

read/write select bit high. The EEPROM acknowl-

edges the device address and serially clocks out the

data word. The microcontroller should respond with a

²no ACK² signal (high) followed by a stop condition.

(refer to Random read timing).

Sequential reads are initiated by either a current ad-

dress read or a random address read. After the

microcontroller receives a data word, it responds with an

acknowledgment. As long as the EEPROM receives an

acknowledgment, it will continue to increment the data

word address and serially clock out sequential data

words. When the memory address limit is reached, the

data word address will roll over and the sequential read

continues. The sequential read operation is terminated

when the microcontroller responds with a

²no ACK² sig-

nal (high) followed by a stop condition.

P

D e v i c e a d d r e s s

W o r d a d d r e s s

A C K

S t o p

S t a r t

S D A

A C K

N o A C K

S

A C K

D A T A

S

0

D e v i c e a d d r e s s

S t a r t

R a n d o m R e a d T i m i n g

0 0

S e q u e n t i a l R e a d T i m i n g

P

D e v i c e a d d r e s s

D A T A n

S t o p

S t a r t

S D A

A C K

S

A C K

D A T A n + 1

D A T A n + x

N o A C K

V a l i d

V a l i d

S C L

S D A

S D A

O U T

S C L

S D A

8 t h b i t

A C K

W o r d n

S t o p

C o n d i t i o n

S t a r t

C o n d i t i o n