ht82k95ee Holtek Semiconductor Inc., ht82k95ee Datasheet - Page 19

• Manufacturer Part Number: ht82k95ee
• Description: Ht82k95ee/ht82k95ae -- Usb Multimedia Keyboard Encoder 8-bit Mcu
• Manufacturer: Holtek Semiconductor Inc.

Rev. 1.20
Read operations
The data EEPROM 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 1 .
Current address read
The internal data word address counter maintains the
last address accessed during the last read or write op-
eration, incremented by one. This address stays valid
between operations as long as the chip power is main-
tained. The address roll over during read from the last
byte of the last memory page to the first byte of the
Acknowledge Polling Flow
Sequential Read Timing
Random Read Timing
Current Read Timing
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first page. The address roll over during write from the
last byte of the current page to the first byte of the
same page. Once the device address with the
read/write select bit set to one is clocked in and ac-
knowledged by the EEPROM, the current address
data word is serially clocked out. The microcontroller
should respond a No ACK (High) signal and following
stop condition (refer to Current read timing).
Random read
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
(refer to Random read timing).
Sequential read
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 no ACK sig-
nal (high) followed by a stop condition.
no ACK signal (high) followed by a stop condition.
HT82K95EE/HT82K95AE
August 28, 2006