UPD784026 Renesas Electronics Corporation., UPD784026 Datasheet - Page 162

• Manufacturer Part Number: UPD784026
• Description: 16/8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

(3) When specified as control signal input/output
122
By setting (1) bits of the port 3 mode control register (PMC3), port 3 can be used as control signal input or output bit-wise
irrespective of the setting of the port 3 mode register (PM3). When a pin is used as a control signal, the control signal status
can be seen by executing a port read instruction.
(a) When port is control signal output
(b) When port is control signal input
When the port 3 mode register (PM3) is set (1), the control signal pin level can be read by executing a port read
instruction.
When PM3 is reset (0), the PD784026 internal control signal status can be read by executing a port read instruction.
Remark
Only the port 3 mode register (PM3) is set (1), control signal pin levels can be read by executing a port read instruction.
For bit 3 (P33) of port 3, the name “SB0” is a reserved word in the NEC assembler package. In the C
compiler, it is defined as an sfr variable by the # pragma sfr directive.
Internal Bus
(Output)
Control
Figure 5-35 Control Specification
RD
CHAPTER 5 PORT FUNCTIONS
PM3n = 0
Control (Input)
PM3n = 1
P3n
n = 0-7