CAT24WC08W Datasheet, PDF (8/14 Pages) Catalyst Semiconductor – Serial EEPROM

CAT24WC01/02/04/08/16
Selective Read
operations. After the 24WC01/02/04/08/16 sends initial
Selective READ operations allow the Master device to
select at random any memory location for a READ
operation. The Master device first performs a ‘dummy’
write operation by sending the START condition, slave
address and byte address of the location it wishes to
read. After the CAT24WC01/02/04/08/16 acknowledge
the word address, the Master device resends the START
8-bit byte requested, the Master will respond with an
acknowledge which tells the device it requires more
data. The CAT24WC01/02/04/08/16 will continue to
output an 8-bit byte for each acknowledge sent by the
Master. The operation is terminated when the Master
fails to respond with an acknowledge, thus sending the
STOP condition.
condition and the slave address, this time with the R/W
The data being transmitted from the CAT24WC01/02/
bit set to one. The CAT24WC01/02/04/08/16 then
04/08/16 is outputted sequentially with data from address
responds with its acknowledge and sends the 8-bit byte
requested. The master device does not send an
acknowledge but will generate a STOP condition.
ts Sequential Read
r _{The Sequential READ operation can be initiated by}
either the immediate Address READ or Selective READ
N followed by data from address N+1. The READ
operation address counter increments all of the
CAT24WC01/02/04/08/16 address bits so that the entire
memory array can be read during one operation. If more
than the E (where E = 255 for 24WC02, 511 for 24WC04,
1023 for 24WC08, and 2047 for 24WC16) bytes are read
out, the counter will “wrap around” and continue to clock
out data bytes. If N = E (where E = 127 for the
CAT24WC01) the counter will not 'wrap around'.
d ^Pa _{Figure 8. Immediate Address Read Timing}
e _S
T
S
u _{BUS ACTIVITY: A}
SLAVE
T
MASTER ^R ADDRESS
O
T
P
tin ^{SDALINE S}
P
A
N
C
DATA
O
K
A
n_C
K
o _SCL
8
9
Disc^SDA
8TH BIT
DATA OUT
NO ACK
STOP
5020 FHD F10
Doc. No. 1022, Rev. O
© Catalyst Semiconductor, Inc.
8
Characteristics subject to change without notice