3 high impedance control, 4 special output – Epson S1C63558 User Manual

Page 44

EPSON

S1C63558 TECHNICAL MANUAL

CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Output Ports)

4.5.3 High impedance control

The terminal output status of the output ports can be set to a high impedance status. This control is done
using the high impedance control register (RxxHIZ) corresponding to each output port (Rxx).
When "1" is written to the high impedance control register, the corresponding output port terminal goes
into high impedance status. When "0" is written, the port outputs a signal according to the data register.

4.5.4 Special output

In addition to the regular DC output, special output can be selected for the output ports R00–R03 and
R10–R13 as shown in Table 4.5.4.1 with the software.
Figure 4.5.4.1 shows the configuration of the R00–R03 and R10–R13 output ports.

Table 4.5.4.1 Special output

Terminal

R13
R12
R11
R10
R03
R02
R01
R00

Special output

HFO

HDO

XRMUTE

XTMUTE

FOUT

TOUT

XBZ

Output control register

CHFO

CHDO

CRMO

CTMO

FOUTE
PTOUT

BZOUT

XBZOUT

Data bus

FOUTE

R03

R03HIZ

FOUT

R03
(FOUT)

PTOUT

R02

R02HIZ

TOUT

R02
(TOUT)

BZOUT

R01

R01HIZ

R01
(BZ)

XBZOUT

R00

R00HIZ

XBZ

R00
(XBZ)

Data bus

CHFO

R13

R13HIZ

HFO

R13
(HFO)

CHDO

R12

R12HIZ

HDO

R12
(HDO)

CRMO

R11

R11HIZ

XRMUTE

R11
(XRMUTE)

CTMO

R10

R10HIZ

XTMUTE

R10
(XTMUTE)

Fig. 4.5.4.1(a) Configuration of R00–R03 output ports Fig. 4.5.4.1(b) Configuration of R10–R13 output ports

At initial reset, the output port data register is set to "1" and the high impedance control register is set to
"0". Consequently, the output terminal goes high (V

When using the output port (R00–R03, R10–R13) as the special output port, fix the data register (R00–R03,
R10–R13) at "1" and the high impedance control register (R00HIZ–R03HIZ, R10HIZ–R13HIZ) at "0" (data
output). The respective signal should be turned ON and OFF using the special output control register.