Epson S1C63558 - Manual (Page 43)

S1C63558 TECHNICAL MANUAL EPSON 33
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Output Ports)
4.5 Output Ports (R00–R03, R10–R13 and R20–R23)
4.5.1 Configuration of output ports
The S1C63558 has 12 bits general output ports.
Output specifications of the output ports can be selected individually with the mask option. Two kinds of
output specifications are available: complementary output and N-channel open drain output.
Figure 4.5.1.1 shows the configuration of the output port.
V DD
V SS
Rxx
Data bus
Address
Data register
Address
High impedance
control register
Mask option
Fig. 4.5.1.1 Configuration of output port
The R00 to R03 output terminals are shared with the buzer/clock outputs (XBZ, BZ, TOUT, FOUT). The
R10 to R13 output terminals are shared with the tone/pulse dialer outputs (XTMUTE, XRMUTE, HDO,
HFO). These functions are selected by the software.
At initial reset, these are all set to the general purpose output port.
Table 4.5.1.1 shows the setting of the output terminals by function selection.
Table 4.5.1.1 Function setting of output terminals
Terminal
name
R00
R01
R02
R03
R10
R11
R12
R13
R20–R23
Special output Terminal status
at initial reset
R00 (HIGH output)
R01 (HIGH output)
R02 (HIGH output)
R03 (HIGH output)
R10 (HIGH output)
R11 (HIGH output)
R12 (HIGH output)
R13 (HIGH output)
R20–R23 (HIGH output)
FOUT
R00
R01
R02
FOUT
R10
R11
R12
R13
R20–R23
XRMUTE
R00
R01
R02
R03
R10
XRMUTE
R12
R13
R20–R23
XTMUTE
R00
R01
R02
R03
XTMUTE
R11
R12
R13
R20–R23
TOUT
R00
R01
TOUT
R03
R10
R11
R12
R13
R20–R23
BZ
R00
BZ
R02
R03
R10
R11
R12
R13
R20–R23
XBZ
XBZ
R01
R02
R03
R10
R11
R12
R13
R20–R23
HFO
R00
R01
R02
R03
R10
R11
R12
HFO
R20–R23
HDO
R00
R01
R02
R03
R10
R11
HDO
R13
R20–R23
When using the output port as the special output port, the data register must be fixed at "1" and the high
impedance control register must be fixd at "0" (data output).
4.5.2 Mask option
Output specifications of the output ports can be selected with the mask option.
Either complementary output or N-channel open drain output can be selected individually (1-bit units).
However, when N-channel open drain output is selected, do not apply a voltage exceeding the power
supply voltage to the output port.