M37221 Mitsubishi, M37221 Datasheet - Page 38

• Manufacturer Part Number: M37221
• Description: SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER with ON-SCREEN DISPLAY CONTROLLER
• Manufacturer: Mitsubishi

The display position in the vertical direction is determined by count-
ing the horizontal sync signal (H
the rising edge (falling edge) of H
chine cycle of rising edge (falling edge) of V
from rising edge (falling edge) of V
edge) of H
for avoiding jitter. The polarity of H
lect with the CRT port control register (address 00EC
refer to (8) CRT Output Pin Control.
Note: When bits 0 and 1 of the CRT port control register (address
Fig. 39. Supplement explanation for display position
38
V
V
signal in
microcomputer
Period of counting
H
H
signal input
When bits 0 and 1 of the CRT port control register (address
00EC
Note: Do not generate falling edge of H
SYNC
SYNC
SYNC
SYNC
00EC
is determined by counting falling edge of H
rising edge of V
fer to Figure 39).
16
SYNC
signal input
control
signal
edge of V
jitter.
) are set to “1” (negative polarity)
16
) are set to “1” (negative polarity), the vertical position
signal needs enough time (2 machine cycles or more)
SYNC
SYNC
control signal in microcomputer to avoid
control signal in the microcomputer (re-
(Note)
SYNC
SYNC
SYNC
1
SYNC
Not count
( at f(X
0.125 to 0.25 [ s]
). At this time, it starts to count
signal from after about 1 ma-
2
signal to rising edge (falling
and V
SYNC
IN
3
SYNC
) = 8MHz)
signal near rising
SYNC
4
signal. So interval
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER
SYNC
5
signals can se-
16
). For details.
signal after
M37221EF-XXXSP,M37221EFSP
Fig. 40. Structure of vertical position register
The horizontal position is common to all blocks, and can be set in 64
steps (where 1 step is 4T
as values “00
register (address 00E0
register is shown in Figure 41.
Fig. 41. Structure of horizontal position register
7
7
16
with ON-SCREEN DISPLAY CONTROLLER
” to “3F
MITSUBISHI MICROCOMPUTERS
16
16
). The structure of the horizontal position
C
” in bits 0 to 5 of the horizontal position
0
, T
0
C
Vertical position registers 1, 2
(CV1 : address 00E1
(CV2 : address 00E2
being the display oscillation period)
Horizontal display start positions
Horizontal position register
(HR : address 00E0
Vertical display start positions
64 steps from “00
(1 step is 4TC)
128 steps from “00
16
16
16
16
)
16
)
)
” to “3F
” to “7F
16
16
”
”