HD66766R Datasheet, PDF (47/97 Pages) Hitachi Semiconductor – 132 x 176-dot Graphics LCD Controller/Driver for 65K Colors

HD66766R
Rev. 1.0-1 / September 2002
Note the following when using high-speed RAM write mode.
Notes: 1. The logical and compare operation cannot be used.
2. Data is written to RAM each four words. When an address is set, the lower two bits in the
address must be set to the following values.
*When I/D0=0, the lower two bits in the address must be set to “11” and be written to RAM.
*When I/D0=1, the lower two bits in the address must be set to “00” and be written to RAM.
3. Data is written to RAM each four words. If less than four words of data is written to RAM,
the last data will not be written to RAM.
4. When the index register and RAM data write (“22”H) have been selected, the data is always
written first. RAM cannot be written to and read from at the same time. HWM must be set
to “0” while RAM is being read.
5. High-speed and normal RAM write operations cannot be executed at the same time. The
mode must be switched and the address must then be set.
6. When high-speed RAM write is used with a window address-range specified, dummy write
operation may be required to suit the window address range-specification. Refer to the High-
Speed RAM Write in the Window Address section.
Table 30 Comparison between Normal and High-Speed RAM Write Operations
Logical operation function
Compare operation function
Write mask function
RAM address set
RAM read
RAM write
Window address
Normal RAM Write
(HWM=0)
Can be used
Can be used
Can be used
Can be specified by word
Can be read by word
Can be written by word
Can be set by word
High-Speed RAM Write
(HWM=1)
Cannot be used
Cannot be used
Can be used
ID0 bit=0: Set the lower two bits to 11
ID0 bit=1: Set the lower two bits to 00
Cannot be used
Dummy write operations may have to be
inserted according to a window address-
range specification
Can be set by four words
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