M37221M6_03 Datasheet, PDF (6/62 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER with ON-SCREEN DISPLAY CONTROLLER

MITSUBISHI MICROCOMPUTERS
M37221M6-XXXSP
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER
with ON-SCREEN DISPLAY CONTROLLER
PIN DESCRIPTION (continued)
P52/R,
P53/G,
P54/B,
P55/OUT1
Output port P5
CRT output
Output
Output
Ports P52–P55 are a 4-bit output port. The output structure is CMOS output.
Pins P52–P55 are also used as CRT output pins R, G, B, OUT1 respectively. The output
structure is CMOS output.
HSYNC
HSYNC input
Input
This is a horizontal synchronizing signal input for CRT.
VSYNC
VSYNC input
Input
This is a vertical synchronizing signal input for CRT.
D-A
DA output
Output
This is a 14-bit PWM output pin.
Note : As shown in the memory map (Figure 3), port P0 is accessed as a memory at address 00C016 of zero page. Port P0 has the port P0
direction register (address 00C116 of zero page) which can be used to program each bit as an input (“0”) or an output (“1”). The pins
programmed as “1” in the direction register are output pins. When pins are programmed as “0,” they are input pins. When pins are
programmed as output pins, the output data are written into the port latch and then output. When data is read from the output pins, the
output pin level is not read but the data of the port latch is read. This allows a previously-output value to be read correctly even if the
output “L” voltage has risen, for example, because a light emitting diode was directly driven. The input pins are in the floating state, so the
values of the pins can be read. When data is written into the input pin, it is written only into the port latch, while the pin remains in the
floating state.
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