MC-78F0712-KIT Renesas Electronics America, MC-78F0712-KIT Datasheet - Page 73

• Manufacturer Part Number: MC-78F0712-KIT
• Description: KIT REF SYSTEM 78K0 UPD78F0712
• Manufacturer: Renesas Electronics America

Specifications of MC-78F0712-KIT

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

<R>
4.5 Cautions on 1-Bit Manipulation Instruction for Port Register n (Pn)
output latch value of an input port that is not subject to manipulation may be written in addition to the targeted bit.
When a 1-bit manipulation instruction is executed on a port that provides both input and output functions, the
Therefore, it is recommended to rewrite the output latch when switching a port from input mode to output mode.
<Example>
Explanation:
P14, P16,
P17
Port 1 output latch
0
P13
0
0
When P13 is an output port, P14, P16, and P17 are input ports (all pin statuses are high level), and
the port latch value of port 1 is 00H, if the output of output port P13 is changed from low level to
high level via a 1-bit manipulation instruction, the output latch value of port 1 is D8H.
The targets of writing to and reading from the Pn register of a port whose PMnm bit is 1 are the
output latch and pin status, respectively.
A 1-bit manipulation instruction is executed in the following order in the PD78F0711 and 78F0712.
<1> The Pn register is read in 8-bit units.
<2> The targeted one bit is manipulated.
<3> The Pn register is written in 8-bit units.
In step <1>, the output latch value (0) of P13, which is an output port, is read, while the pin statuses
of P14, P16, and P17, which are input ports, are read. If the pin statuses of P14, P16, and P17 are
high level at this time, the read value is D0H.
The value is changed to D8H by the manipulation in <2>.
D8H is written to the output latch by the manipulation in <3>.
1-bit manipulation instruction for P10 bit
<1> Port register 1 (P1) is read in 8-bit units.
<2> Set the P13 bit to 1.
<3> Write the results of <2> to the output latch of port register 1 (P1)
0
in 8-bit units.
Pin status: High-level
Low-level output
0
In the case of P13, an output port, the value of the port output latch (0) is read.
In the case of P14, P16, P17, input ports, the pin status (1) is read.
0
Figure 4-13. Bit Manipulation Instruction (P13)
0
CHAPTER 4 PORT FUNCTIONS
0
User’s Manual U17890EJ2V0UD
1-bit manipulation
instruction
(set1 P1.3)
is executed for P13
bit.
P14, P16,
P17
Port 1 output latch
1
P13
1
0
1
Pin status: High-level
High-level output
1
0
0
0
71