UPD784938 Datasheet, PDF (201/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 7 REAL-TIME OUTPUT FUNCTION
7.1 Configuration and Function
The real-time output function is implemented by hardware, including primarily port 0 and the port 0 buffer registers (P0H, P0L),
shown in Figure 7-1.
The real-time output function refers to the transfer to the output latch by hardware of data prepared in the P0H and P0L
beforehand, simultaneously with the generation of an interrupt from timer/event counter 1 or external interrupt, and its output
off-chip. The pins that output the data off-chip are called real-time output ports.
The following two kinds of real-time output data are handled:
• 4 bits × 2 channels
• 8 bits × 1 channel
By combining the real-time output function with the macro service function described later, the functions of a pattern generator
with programmable timing are implemented without software intermediation.
This is ideally suited to stepping motor control, for example.
Figure 7-1 shows the block diagram of the real-time output port.
Preliminary User’s Manual U13987EJ1V0UM00
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