Epson S1C63558 Output Ports, 4.5.1 Configuration of output ports, 4.5.2 Mask option, 4.5Output Ports (R00–R03, R10–R13and R20–R23), Rxx

CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Output Ports)

4.5Output 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.

Data bus

Address VDD

High impedance control register

	Mask option
Data register	Rxx

Address

VSS

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	Terminal status				Special output
name	at initial reset	FOUT	TOUT	BZ	XBZ	HFO	HDO	XRMUTE	XTMUTE
R00	R00 (HIGH output)	R00	R00	R00	XBZ	R00	R00	R00	R00
R01	R01 (HIGH output)	R01	R01	BZ	R01	R01	R01	R01	R01
R02	R02 (HIGH output)	R02	TOUT	R02	R02	R02	R02	R02	R02
R03	R03 (HIGH output)	FOUT	R03	R03	R03	R03	R03	R03	R03
R10	R10 (HIGH output)	R10	R10	R10	R10	R10	R10	R10	XTMUTE
R11	R11 (HIGH output)	R11	R11	R11	R11	R11	R11	XRMUTE	R11
R12	R12 (HIGH output)	R12	R12	R12	R12	R12	HDO	R12	R12
R13	R13 (HIGH output)	R13	R13	R13	R13	HFO	R13	R13	R13
R20–R23	R20–R23 (HIGH output)	R20–R23	R20–R23	R20–R23	R20–R23	R20–R23	R20–R23	R20–R23	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.

S1C63558 TECHNICAL MANUAL EPSON 33