NEC PD17062 - Manual (Page 252)

252
µ
PD17062
20.4.4 Control Data Select Data
The term control data refers to the data that specifies the character size, display position, and color of a
character pattern on the screen. This data is held in CROM (at
×××
FH).
The control data select data is held in VRAM and selects control data in CROM.
The 6 bits of the data field correspond to b 9 to b 4 of the CROM address. Similarly to the pattern select data,
the control data select data also requires that a CROM bank be specified. A CROM bank is specified using
CROMBNK (b 0 at 30H) in the register file.
Fig. 20-5 Relationship between the Control Data and CROM Address
b
7
b
6
b
5
b
4
b
3
b
2
b
1
b
0
1 0
b
11
1
b
0
1 1 1 1
Bank data
BANK0: 0
BANK1: 1
Data in VRAM
CROM address