7220 Datasheet, PDF (113/303 Pages) Renesas Technology Corp – 8-BIT SINGLE-CHIP MICROCOMPUTER

FUNCTIONAL DESCRIPTION
2.11 CRT display function
2.11.7 CRT output pin control
CRT display output pins R, G, B, and OUT1 are also used for ports P52–P55 respectively. When clearing
the corresponding bits of the port P5 direction register (address 00CB16) to “0,” the pins are set for CRT
output pins, when setting to “1,” the pins are set for general-purpose port P5. Pin PUT2 is also used for
port P10. When clearing bit 7 of the CRT control register (address 00EA16) to “0,” the pin is set for port P10,
when setting to “1,” the pin is set for pin OUT2.
Immediately after reset release, because the port P5 direction register is reset, they become CRT output
pins R, G, B, and OUT.
Bits 0 to 4 of the CRT port control register (address 00EC16) can determine HSYNC and VSYNC input polarity
and R, G, B, OUT1, and OUT2 output polarity. When clearing corresponding bits to “0,” positive polarity
is selected, when setting to “1,” negative polarity is selected.
Figure 2.11.17 shows the CRT port control.
CRT Port Control Register
b7 b6 b5 b4 b3 b2 b1 b0
CRT port control register (CRTP) [Address 00EC16]
B
Name
0 HSYNC input polarity
switch bit (HSYC)
1 VSYNC input polarity
switch bit (VSYC)
2 R, G, B output polarity
switch bit (R/G/B)
3 OUT2 output polarity
switch bit (OUT2)
4 OUT1 output polarity
switch bit (OUT1)
5 R signal output switch bit
(OP5)
6 G signal output switch bit
(OP6)
7 B signal output switch bit
(OP7)
Functions
0 : Positive polarity
1 : Negative polarity
0 : Positive polarity
1 : Negative polarity
0 : Positive polarity
1 : Negative polarity
0 : Positive polarity
1 : Negative polarity
0 : Positive polarity
1 : Negative polarity
0 : R signal output
1 : MUTE signal output
0 : G signal output
1 : MUTE signal output
0 : B signal output
1 : MUTE signal output
Fig. 2.11.17 CRT port control register (address 00EC16)
After reset R W
0 RW
0 RW
0 RW
0 RW
0 RW
0 RW
0 RW
0 RW
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7220 Group User’s Manual