HT24LC16
·
Acknowledge polling
The 8th bit device address is the read/write operation
select bit. A read operation is initiated if this bit is high
and a write operation is initiated if this bit is low.
To maximize bus throughput, one technique is to allow
the master to poll for an acknowledge signal after the
start condition and the control byte for a write com-
mand have been sent. If the device is still busy imple-
menting its write cycle, then no ACK will be returned.
The master can send the next read/write command
when the ACK signal has finally been received.
If the comparison of the device address succeed the
EEPROM will output a zero at ACK bit. If not, the chip will
return to a standby state.
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Write Operations
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·
Byte write
A write operation requires an 8-bit data word address
following the device address word and acknowledg-
ment. Upon receipt of this address, the EEPROM will
again respond with a zero and then clock in the first
8-bit data word. After receiving the 8-bit data word, the
EEPROM will output a zero and the addressing de-
vice, such as a microcontroller, must terminate the
write sequence with a stop condition. At this time the
EEPROM enters an internally-timed write cycle to the
nonvolatile memory. All inputs are disabled during this
write cycle and EEPROM will not respond until write is
complete (refer to Byte write timing).
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Acknowledge Polling Flow
Write protect
·
Page write
The 16K EEPROM is capable of a 16-byte page write.
A page write is initiated in the same way as a byte
write, but the microcontroller does not send a stop con-
dition after the first data word is clocked in. Instead, af-
ter the EEPROM acknowledges the receipt of the first
data word, the microcontroller can transmit up to 15
more data words. The EEPROM will respond with a
zero after each data word received. The
microcontroller must terminate the page write sequence
with a stop condition (refer to Page write timing).
The data word address lower four bits are internally in-
cremented following the receipt of each data word.
The higher data word address bits are not incre-
mented, retaining the memory page row location.
·
The HT24LC16 has a write-protect function and pro-
gramming will then be inhibited when the WP pin is
connected to VCC. Under this mode, the HT24LC16 is
used as a serial ROM.
·
Read operations
The HT24LC16 supports three read operations,
namely, current address read, random address read
and sequential read. During read operation execution,
the read/write select bit should be set to ²1².
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Byte Write Timing
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Page Write Timing
Rev. 1.60
4
June 25, 2010
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
