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FUNCTIONAL DESCRIPTION
2.3 Memory assignment
(4) Border selection register (address 00E5
The border selection register is assigned to address 00E5
used to set the border for blocks 1 and 2 by using one bit each. Bits 1 and 3 to 7 are not used.
(5) Color registers (addresses 00E6
Color registers 0 to 3 are assigned to addresses 00E6
and are used to set character output, blank output and character background color by CRT output
(R, G, B, OUT1). Bit 0 is not used.
(6) CRT control register (address 00EA
The CRT control register is assigned to address 00EA
to set display on/off for each block. Bits 3 to 6 are not used.
(7) CRT port control register (address 00EC
The CRT port control register is assigned to address 00EC
used to set the input polarity (H
2.3.9 A-D control registers (addresses 00EE
The A-D control register 1 is assigned to address 00EE
00EF
. Both registers consist of 8 bits
16
The A-D control register 1 is used to select analog input pins and hold the results of comparator operation.
Bits 3 and 5 to 7 are not used.
The A-D control register 2 is used to set the internal analog voltage. Bits 6 and 7 are not used.
2.3.10 Timer registers (addresses 00F0
The timer registers are assigned to addresses 00F0
in this area when writing, but only the timer is read when reading.
To write data to address 00F1
that, the timer 2 contents are decremented by synchronizing with the clock pulse but the timer 2 latch
contents are not changed. Accordingly, when reading data at address 00F1
read out at the time.
Addresses
00F0
16
00F1
16
00F2
16
00F3
16
Fig. 2.3.7 Access to timer registers
2-18
to 00E9
16
)
16
and V
SYNC
SYNC
16
to 00F3
16
, for example, the data are stored to the timer 2 latch and timer 2. After
16
Timer 1
Timer 2
Timer 3
Timer 4
7220 Group User's Manual
)
16
. This register consists of 8 bits, and is
16
)
16
to 00E9
. All color registers consist of 8 bits,
16
16
. This register consists of 8 bits, and is used
16
)
16
. This register consists of 8 bits, and is
16
) and the output polarity (R, G, B, OUT1 and OUT2).
and 00EF
)
16
, the A-D control register 2 is assigned to address
16
)
16
to 00F3
. Both the timer and timer latch are written
16
16
Data setting
Reading the contents of timer 2
, the contents of timer 2 is
16
Timer 2 latch
Data loading at timer 2
overflow
Timer 2
Counting
(down count)
At read access
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