
S1C88348/317/316/308 TECHNICAL SOFTWARE
EPSON
II-23
6 OUTPUT PORTS (R PORTS)
I/O Map
Specifications
Control of output port (R port)
(1) initoutput_normal, output_normal: Normal DC output
Sets the R3x port to complementary output and outputs HIGH and LOW to R35–R37.
(2) init_hiz, output_hiz: High impedance output control
First sets the R5x port to complementary output and then switches between high impedance output
and complementary output to operate the high impedance control register.
(3) fout_init, fout_control: FOUT output control
Controls the turning ON/OFF of the FOUT output.
Notes
(1) Besides normal DC output, output port terminals are
shared with the special output shown in Table 6.1, and
which is used can be selected in software. When using
special output, it should be noted so that the port
cannot be used as output port.
For control of special output except for FOUT output
(R34 terminal), see the following chapters:
Table 6.1 Special output
TOUT output (R27) .................................. "12 PROGRAMMABLE TIMER"
CL output (R25), FR output (R26) .......... "13 LCD CONTROLLER"
BZ output (R50) ........................................ "14 SOUND GENERATOR"
(2) Please note that in accordance with the bus mode and system controller settings or when using bus
release for DMA transfer, the following output port terminals are used for the address bus, RD/WR
signals, CE3–CE0 signals and BACK outputs and cannot be used as an output port.
(3) R35–R37 terminals can be used only when the S1C883xx chip is being shipped.
(4) The S1C88308 does not have R51 terminal.
Address Bit
Name
00FF40 D7
D6
D5
D4
D3
D2
D1
D0
–
FOUT2
FOUT1
FOUT0
FOUTON
WDRST
TMRST
TMRUN
SR R/W
Function
Comment
–
FOUT frequency selection
FOUT output control
Watchdog timer reset
Clock timer reset
Clock timer Run/Stop control
"0" when being read
Constantly "0" when
being read
10
–
0
–
0
R/W
W
R/W
–
On
Reset
Run
–
Off
No operation
Stop
FOUT2
0
1
FOUT1
0
1
0
1
FOUT0
0
1
0
1
0
1
0
1
Frequency
fOSC1 / 1
fOSC1 / 2
fOSC1 / 4
fOSC1 / 8
fOSC3 / 1
fOSC3 / 2
fOSC3 / 4
fOSC3 / 8
Output port
R25
R26
R27
R34
R50
Special output
CL output
FR output
TOUT output
FOUT output
BZ output