UPD784915B Datasheet, PDF (29/86 Pages) NEC – 16-BIT SINGLE-CHIP MICROCONTROLLERS

µPD784915B, 784916B
3.5 Real-time Output Port
A real-time output port consists of a port output latch and a buffer register (refer to Figure 3-5).
The function to transfer the data prepared in advance in the buffer register to the output latch when a trigger such
as a timer interrupt occurs, and output the data to an external device is called a real-time output function. A port used
in this way is called a real-time output port (RTP).
Table 3-4 shows the real-time output ports of the µPD784916B.
Table 3-5 shows the trigger sources of RTPs.
Figure 3-5. Configuration of RTP
Buffer register
Output trigger
Port output latch
Port
RTP
RTP0
RTP8
Alternate
Function
Port 0
Port 8
Table 3-4. Bit Configuration of RTP
Number of Bits of
Real-Time Output Data
4 bits × 2 channels or
8 bits × 1 channel
1 bit × 1 channel and 2
bits × 1 channel
Number of Bits That
Can Be Specified as
RTP
4-bit units
1-bit units
Remark
—
Pseudo VSYNC output : 1 channel (RTP80)
Head amplifier switch : 1 channel (RTP82)
Chrominance rotation signal output: 1
channel (RTP83)
Table 3-5. Trigger Sources of RTP
RTP
RTP0
RTP8
Trigger Source INTCR00
High-order 4 bits
Low-order 4 bits
All 8 bits
Bit 0
Bits 2 and 3
√
INTCR01
√
√
INTCR02
√
√
√
INTCR13
√
INTCR50
√
INTP0
Remark
√
√
Note 1
Note 2
Notes 1. Select one of the four trigger sources.
2. When the real-time output port mode is set by the port mode control register 8 (PMC8), the HASW and
ROT-C signals that are set by the head amplifier switch output control register (HAPC) are directly output.
The HASW and ROT-C signals are synchronized with HSW output (TM0-CR00 coincidence signal).
However, the set signal is output immediately when the HAPC register is rewritten.
29