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4.5.4 I/O memory of output ports
Table 4.5.4.1 shows the I/O address and the control bits for the output port.
Register
Address
D3
D2
R02
R03
BZ
BZ
FOUT
0FCH
R/W
∗1
Initial value at initial reset
∗2
Not set in the circuit
R00–R03: Output port data (0FCH)
Sets the output data for the output ports.
When "1" is written: High output
When "0" is written: Low output
Reading: Valid
The output port terminals output the data written to the corresponding registers (R00–R03) without
changing it. When "1" is written to the register, the output port terminal goes high (V
written, the output port terminal goes low (V
At initial reset, these registers are all set to "0".
R02 (when FOUT is selected): Special output control (0FCH•D2)
Controls the FOUT (clock) output.
When "1" is written: Clock output
When "0" is written: Low level (DC) output
Reading: Valid
When "1" is written to the FOUT (R02) register, the FOUT (R02) terminal outputs the FOUT signal. When
"0" is written, the terminal goes low.
At initial reset, this register is set to "0".
R02, R03 (when buzzer output is selected): Special output port data (0FCH•D2, D3)
Controls the buzzer output.
When "1" is written: Buzzer output
When "0" is written: Low level (DC) output
Reading: Valid
The BZ and BZ outputs can be controlled by writing data to the R02 and R03 registers.
At initial reset, these registers are set to "0".
4.5.5 Programming note
The FOUT and buzzer output signals may produce hazards when the output ports R02 and R03 are
turned on or off.
E0C6006 TECHNICAL MANUAL
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Output Ports)
Table 4.5.4.1 Control bits of output port
∗1
D1
D0
Name Init
R03
0
BZ
0
R01
R00
R02
0
BZ/FOUT
0
R01
0
R00
0
∗3
Always "0" being read
∗4
Reset (0) immediately after being read
SS
1
0
High
Low
R03 output port data
On
Low
Signal on/off when BZ is selected. (mask option)
High
Low
R02 output port data
On
Low
Signal on/off when BZ/FOUT is selected. (mask option)
High
Low
R01 output port data
High
Low
R00 output port data
).
EPSON
Comment
∗5 Undefined
), and when "0" is
DD
21
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