UPD6466GS datasheet(50/70 Pages) NEC

50 / 70 page

µPD6466

4.3 2-Byte Successive Commands

D15-D8

MSB first

DATA

D0-D7

D7-D0

D8-D15

1st byte

2nd byte

1st byte

2nd byte

DATA

CLK

LSB first

D7-D0

D8-D15

2nd byte

The 2-byte successive command writes characters to the video RAM. To successively write characters without

changing the blinking data, reverse specification data, and VC2 specification data, first transfer the first byte and then

transfer the second byte (character address).

To change the contents of the above data, change the contents of the data and then input the command from the

first byte after terminating the 2-byte successive command once (by either making CS high or transferring the 2-byte

successive command end code).

However, the command cannot be transferred successively across banks.

When the low-order bank is selected, the command can be transferred successively in a character address range

of 000H to 0FFH; when the high-order bank is selected, the character address range is from 100H to 1FFH.

It is recommended that characters that are frequently used be stored to both the high-order and low-order banks.

To write a character that across the banks, complete successive transfer once, and then transfer the command

from the first byte after changing the bank.

UPD6466GS Datasheet(PDF) 50 Page - NEC