S1C63454 TECHNICAL MANUAL
EPSON
35
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Output Ports)
FOUTE: FOUT output control register (FF06H•D3)
Controls the FOUT output.
When "1" is written: FOUT output ON
When "0" is written: FOUT output OFF
Reading: Valid
By writing "1" to the FOUTE register when the R03 register has been set to "1" and the R03HIZ register
has been set to "0", an FOUT signal is output from the R03 terminal. When "0" is written, the R03 terminal
goes high (V
DD
).
When using the R03 output port for DC output, fix this register at "0".
At initial reset, this register is set to "0".
FOFQ0, FOFQ1: FOUT frequency selection register (FF06H•D0, D1)
Selects a frequency of the FOUT signal.
Table 4.5.5.2 FOUT clock frequency
FOFQ1
1
1
0
0
FOFQ0
1
0
1
0
Clock frequency
f
OSC3
f
OSC1
f
OSC1
×
1/8
f
OSC1
×
1/64
At initial reset, this register is set to "0".
PTOUT: TOUT output control register (FFC1H•D2)
Controls the TOUT output.
When "1" is written: TOUT output ON
When "0" is written: TOUT output OFF
Reading: Valid
By writing "1" to the PTOUT register when the R02 register has been set to "1" and the R02HIZ register
has been set to "0", the TOUT signal is output from the R02 terminal. When "0" is written, the R02 termi-
nal goes high (V
DD
).
When using the R02 output port for DC output, fix this register at "0".
At initial reset, this register is set to "0".
4.5.6 Programming notes
(1) When using the output port (R02, R03) as the special output port, fix the data register (R02, R03) at "1"
and the high impedance control register (R02HIZ, R03HIZ) at "0" (data output).
Be aware that the output terminal is fixed at a low (V
SS
) level the same as the DC output if "0" is
written to the R02 and R03 registers when the special output has been selected.
Be aware that the output terminal shifts into high impedance status when "1" is written to the high
impedance control register (R02HIZ, R03HIZ).
(2) A hazard may occur when the FOUT signal and the TOUT signal are turned ON and OFF.
(3) When f
OSC3
is selected for the FOUT signal frequency, it is necessary to control the OSC3 oscillation
circuit before output.
Refer to Section 4.3, "Oscillation Circuit", for the control and notes.