
I-36
EPSON
S1C62740 TECHNICAL HARDWARE
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Output Ports)
Table 4.5.3 lists the output ports' control bits and their addresses.
Control of output
ports
Table 4.5.3 Control bits of output ports
*1 Initial value at the time of initial reset
*5 Constantly "0" when being read
*2 Not set in the circuit
*6 Refer to main manual
*3 Undefined
*7 Page switching in I/O memory is not necessary
*4 Reset (0) immediately after being read
FOR00:
R00 output selection register
(E1HD3)
Selects the output type for the R00 terminal.
When "1" is written: FOUT signal output
When "0" is written: DC output
Reading: Valid
By setting the register FOR00 to "1", R00 is set to FOUT (clock)
output port. When FOR00 is set to "0", R00 become the regular DC
output port.
When the FOUT output is selected, ON/OFF of the signal output
can be controlled by the R00 register.
At initial reset, this register is set to "0".
PTR01:
R01 output selection register
(E9HD3)
Selects the output type for the R01 terminal.
When "1" is written: PTOVF signal output
When "0" is written: DC output
Reading: Valid
By setting the register PTR01 to "1", R01 is set to PTOVF (output
pulse of the programmable timer) output port. When PTR01 is set
to "0", R01 become the regular DC output port.
Address
Comment
Register
D3
D2
D1
D0
Name
Init
1
0
*1
D4H
R00
FOUT
R/W
R03
BZ
R02
BZ
R01
PTOVF
R00
FOUT
0
1
High
On
High
On
High
Off
High
Off
Low
Off
Low
Off
Low
On
Low
On
R01
PTOVF
R02
BZ
R03
BZ
*7
Output port (R03)
Buzzer inverted output
Output port (R02)
Buzzer output
Output port (R01)
PTOVF output
Output port (R00)
FOUT output
E0H
BZFQ
R/W
BZR03
BZR02
0
BZFQ
0
–
0
R03 port output selection
R02 port output selection
Unused
Buzzer frequency selection
Buzzer
2kHz
DC
4kHz
0
BZR02
BZR03
*2
*5
E1H
FOFQ0
R/W
FOR00
0
FOFQ1
FOFQ0
0
–
0
FOUT
DC
FOFQ1
0
FOR00
*2
*5
R00 port output selection
Unused
FOUT frequency selection
0: 512 Hz, 1: 4096 Hz, 2: fOSC1, 3: fOSC3
R
R/W
R
R/W
E9H
PTRST
W
PTR01
0
PTRUN
PTRST
0
–
0
–
R01 port output selection
Unused
Programmable timer Run/Stop
Programmable timer reset (reload)
PTOVF
Run
Reset
DC
Stop
–
PTRUN
R/W
0
R
PTR01
R/W
*2
*5