UPD784938 Datasheet, PDF (203/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 7 REAL-TIME OUTPUT FUNCTION
7.2 Real-time Output Port Control Register (RTPC)
RTPC is an 8-bit register that specifies the function of port 0.
RTPC can be read or written to with an 8-bit manipulation instruction or bit manipulation instruction. Figure 7-2 shows the
format of RTPC.
RESET input clears RTPC to 00H.
Figure 7-2. Real-Time Output Port Control Register (RTPC) Format
7
6
RTPC BYTE 0
5
4
3
2
1
0 Address After reset R/W
0 P0MH EXTR 0 TRGP0 P0ML 0FF2EH
00H
R/W
P0ML
P00 to P03 Function Specification
0 Port mode
1 Real-time output port mode
EXTR TRGP0 Enabling of Data Transfer to Output
Latch from P0H, P0L by INTP0
0
0 Not enabled
(data transfer by INTC10 only)
1
0 Transfer by either Enabled
INTP0 or INTC10 • BYTE = 0:
P0L only
transferred
1
1 Transfer by
• BYTE = 1:
INTP0 only
P0L/P0H
transferred
0
1 Setting prohibited
P0MH
P04 to P07 Function Specification
0 Port mode
1 Real-time output port mode
BYTE Real-Time Output Port Operating Mode
0 4-bit separate real-time output port
1 8-bit real-time output port
Caution When P0ML and P0MH bits are set (to 1), the corresponding port output buffer is turned on and the port
0 output latch contents are output irrespective of the contents of the port 0 mode register (PM0). The
output latch contents should therefore be initialized before making a real-time output port specification.
Preliminary User’s Manual U13987EJ1V0UM00
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