hd66789 Renesas Electronics Corporation., hd66789 Datasheet - Page 18

• Manufacturer Part Number: hd66789
• Description: 528-channel, One-chip Driver For Amorphous Tft Panels With 262,144-color Display Ram, Power Supply Circuit, And Gate Circuit
• Manufacturer: Renesas Electronics Corporation.

HD66789
Block Function
1.
The HD66789 has five high-speed system interfaces: 80-system 18-/16-/9-/8-bit bus and Serial Peripheral
Interface (SPI) port. The interface mode is selected with IM3-0 pins.
The HD66789 has three registers: 16-bit index register (IR), 18-bit write-data register (WDR), and 18-bit
read-data register (RDR). The IR stores index information from control registers and GRAM. The WDR
temporarily stores data to write into the control registers and GRAM, and the RDR temporarily stores data
read from GRAM. Data written into GRAM from the MPU is first written into the WDR and then
automatically written into GRAM by internal operation. Since data are read through the RDR from GRAM,
the data read out first are invalid data and the ensuing data are read out normally.
The execution time for instructions other than oscillation start is 0-clock cycle, which enables consecutively
writing instructions.
Register Selection (8/9/16/18 Parallel Interfaces)
80-system Bus
WR*
0
1
0
1
Values of CS and VLD during RAM Write
CS*
0
1
0
1
Note 1) The VLD setting is only effective with RAM write instructions.
Register Selection (Serial Peripheral Interface)
Start bytes
R/W
0
1
0
1
Rev.0.12, May 09 2003, page 18 of 156
System Interface
RS
0
0
1
1
RD*
1
0
1
0
VLD
0
0
1
1
Operations
Write index to IR
Read internal status
Write into control register and GRAM through WDR
Read from GRAM through RDR
RS
0
0
1
1
Operations
Write data to GRAM. RAM address is updated.
Not write data to GRAM. RAM address is not updated.
Not write data to GRAM. RAM address is updated.
Not write data to GRAM. RAM address is not updated.
Operation
Write index to IR
Read internal status
Write to the control registers or GRAM through WDR
Read from GRAM through RDR
Preliminary