HD66750/1
45
3. Write mode 3: AM1D0 = 10, LG1D0 = 00
This mode is used when the data is written at high speed by vertically shifting bits. It can also be used to
wr it e t he 16-bi dat a for t wo wor ds i nt o t he gra phi cs R AM (C GR AM , deve l op t he font pat er n, or
transfer the BiTBLT as a bit unit. The rotation function (RT2D0) or write-data mask function (WM15D0)
ar e al s o ena bl ed i n t hes e oper at on. Howe ver al hough t he wr it e -dat a m as k func t on m as ks t he bi
pos i on s et wi h t he wr it e -dat a m as k re gi st e r (W M 15D0) at t he odd-t m es (s uc h as t he fi rs or t hi rd)
wr it e t he func t on m as ks t he bi pos i on t hat re ver se d t he s et ng val ue of t he wr it e -dat a m as k re gi st e r
(W M 15D0) at t he eve n-t m es (s uc h as t he s ec ond or four th) wr it e Af ter t he odd-t m es wr it ng, t he
addr es s count e r (A C) aut om at ca y i ncr em ent s by 1 (I /D = 1) or dec re me nt s by 1 (I /D = 0). Af te r t he
even-times writing, the AC automatically increments or decrements by D1 + 16 (I/D = 1) or +1 + 16 (I/D
= 0). The AC automatically jumps to the upper edge after it has reached the lower edge of the graphics
RAM.
WM0
WM15
1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0
DB0
DB15
1 1 1 1 1 1 0 0 0 0 0 1 1 0 0 0
1 1 1 1 1 1 0 0 0 0 0 1 1 0 0 0
0 0 0 0 0 1 1 1 0 0 0 0 1 1 1 1
000H
Write data (1), (2)
CGRAM
010H
020H
Write data (3), (4)
Write data (5), (6)
*
0 0 0 0 0 1 1 1 0 0 0 0 1 1 1 1
1 1 1 1 1 1 0 0 0 0 0 1
1 0 0 0
1 1 1 1 1 1 0 0 0 0 0 1
1 0 0 0
0 0 0 0 0 1 1 1 0 0 0 0
1 1 1 1
0 0 0 0 0 1 1 1 0 0 0 0
1 1 1 1
1 1 1 1 1 1 0 0 0 0 0 1
0 0 0 0 0 1 1 1 0 0 0 0
1 0 0 0
1 1 1 1
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
000H
001H
0 0 1 0 0 0 0 1 1 1 1 1 1 0 0 0
0 0 1 0 0 0 0 1 1 1 1 1 1 0 0 0
0 0 1 0 0 0 0 1 1 1 1 1
1 0 0 0
0 0 1 0 0 0 0 1 1 1 1 1
1 0 0 0
*
*
*
*
* * * * * * * * * * * *
0 0 1 0 0 0 0 1 1 1 1 1
1 0 0 0
7F0H
1) I/D = 1, AM1D0 = 10, LG1D0 = 00, RT2D0 = 010
2) WM15D0 = 0007H
3) AC = 000H
Write data mask:
Write data (1) :
Write data (2) :
Write data (3) :
4-bit rotation
4-bit rotation
4-bit rotation
Operation Examples:
Write data (4) :
Write data (5) :
Write data (6) :
4-bit rotation
4-bit rotation
4-bit rotation
Notes: 1. The bit area data in the RAM indicated by '*' is not changed.
2. After writing to address 7F0H, the AC jumps to 001H.
Figure 28 Writing Operation of Write Mode 3