UPD78F0838 Renesas Electronics Corporation., UPD78F0838 Datasheet - Page 174
UPD78F0838
Manufacturer Part Number
UPD78F0838
Description
8-bit Single-chip Microcontrollers
Manufacturer
Renesas Electronics Corporation.
Datasheet
1.UPD78F0838.pdf
(917 pages)
- Current page: 174 of 917
- Download datasheet (14Mb)
4.6 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.
172
P11 to P17
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:
Port 1 output latch
0
P10
0
0
When P10 is an output port, P11 to 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 P10 is changed from low level to high level
via a 1-bit manipulation instruction, the output latch value of port 1 is FFH.
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 78K0/Dx2.
<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 P10, which is an output port, is read, while the pin statuses
of P11 to P17, which are input ports, are read. If the pin statuses of P11 to P17 are high level at
this time, the read value is FEH.
The value is changed to FFH by the manipulation in <2>.
FFH 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 P10 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 P10, an output port, the value of the port output latch (0) is read.
In the case of P11 to P17, input ports, the pin status (1) is read.
0
Figure 4-34. Bit Manipulation Instruction (P10)
0
Preliminary User’s Manual U19748EJ1V0UD
CHAPTER 4 PORT FUNCTIONS
0
1-bit manipulation
instruction
(set1 P1.0)
is executed for P10
bit.
P11 to P17
Port 1 output latch
1
P10
1
1
1
Pin status: High level
High-level output
1
1
1
1
Related parts for UPD78F0838
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Renesas Technology Corp [Renesas 32-Bit RISC Microcomputer Super RISC engine Family/SH7700 Series]
Manufacturer:
Renesas Electronics Corporation.
Datasheet:
Part Number:
Description:
RENESAS MCU M16C FAMILY / M16C/Tiny SERIES
Manufacturer:
Renesas Electronics Corporation.
Datasheet:
Part Number:
Description:
Renesas Starter Kit for RX210
Manufacturer:
Renesas Electronics Corporation.
Part Number:
Description:
EVALBOARD/Renesas StarterKit for RX630
Manufacturer:
Renesas Electronics Corporation.
Part Number:
Description:
EVALBOARD/Renesas Starter Kit+ for RX63N
Manufacturer:
Renesas Electronics Corporation.
Part Number:
Description:
EVALBOARD/Renesas Starter Kit
Manufacturer:
Renesas Electronics Corporation.
Part Number:
Description:
FLASH PROGRAMMER FOR RENESAS MICROCONTROLLERS
Manufacturer:
Renesas Electronics Corporation.
Part Number:
Description:
Manufacturer:
Renesas Electronics Corporation.
Datasheet:
Part Number:
Description:
Manufacturer:
Renesas Electronics Corporation.
Datasheet:
Part Number:
Description:
Manufacturer:
Renesas Electronics Corporation.
Datasheet:
Part Number:
Description:
Manufacturer:
Renesas Electronics Corporation.
Datasheet:
Part Number:
Description:
Manufacturer:
Renesas Electronics Corporation.
Datasheet:
Part Number:
Description:
Manufacturer:
Renesas Electronics Corporation.
Datasheet:
Part Number:
Description:
Manufacturer:
Renesas Electronics Corporation.
Datasheet:
Part Number:
Description:
Manufacturer:
Renesas Electronics Corporation.
Datasheet: