MC68HC705T16 MOTOROLA [Motorola, Inc], MC68HC705T16 Datasheet - Page 83

• Manufacturer Part Number: MC68HC705T16
• Description: High-density complementary metal oxide semiconductor (HCMOS) microcontroller unit
• Manufacturer: MOTOROLA [Motorola, Inc]

RiEN - Row i display enable
If RiEN bit is set while the horizontal line currently being displayed has already passed the vertical
start position of this recently enabled row, this recently enabled row will not be displayed in this
frame. It will then be displayed in the next frame. That is, RiEN bit has to be set before current
horizontal display line reaches ((RiVP6-RiVP0)x4) for single scan mode or ((RiVP6-RiVP0)x4)x2
for double scan mode to enable display of row i in current frame.
Note that clearing RiEN bit does not clear the corresponding RiCF bit. Hence, care must be taken
before enabling RiINTE and RiEN to avoid interrupt caused by uncleared RiCF before the setting
of RiINTE and RiEN.
9.4.5
RiCHS1, RiCHS0 - Row i character size
There are two predefined numbers of total dots that can be displayed on a horizontal line. The
number of dots per line is a function of character size selection and the size of character dot
matrix. For the special case of 3Hx3V and 12x16 dot matrix, the number of total dots per line is
396; whereas for other combinations of character size and dot matrix, the number is 384 dots per
line. Users can avoid filling the unused bytes in a row since these bytes will not be displayed.
Table 9-2 lists the number of valid character bytes per row.
9.5
The following registers affect the frame of an OSD displays.
MC68HC05T16
1 (set)
0 (clear) –
Address
$2A
Row Control Register 2
Frame
R3CHS1 R3CHS0 R2CHS1 R2CHS0 R1CHS1 R1CHS0 R0CHS1 R0CHS0
–
bit 7
Row i display enabled.
Row i display disabled.
bit 6
RiCHS1
0
0
1
1
bit 5
RiCHS0
ON-SCREEN DISPLAY
0
1
0
1
bit 4
basic - 1Hx1V
Single expanded - 2Hx2V
Double expanded - 3Hx3V
Triple expanded - 4Hx4V
bit 3
Character size of row i
bit 2
bit 1
bit 0
0000 0000
on reset
State
MOTOROLA
TPG
9-13
9