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

Special output

Output control register

R13

HFO

CHFO

R12

HDO

CHDO

R11

XRMUTE

CRMO

R10

XTMUTE

CTMO

R03

FOUT

FOUTE

R02

TOUT

PTOUT

R01

BZ

BZOUT

R00

XBZ

XBZOUT

 

FOUT

 

 

Register

 

 

FOUTE

 

 

Register

R03

 

R03

(FOUT)

 

Register

 

 

R03HIZ

 

 

TOUT

 

 

Register

 

 

PTOUT

 

 

Register

R02

 

R02

(TOUT)

bus

Register

 

R02HIZ

 

Data

BZ

 

Register

 

 

 

 

BZOUT

 

 

Register

R01

 

R01

(BZ)

 

Register

 

 

R01HIZ

 

 

XBZ

 

 

Register

 

 

XBZOUT

 

 

Register

R00

 

R00

(XBZ)

 

Register

 

 

R00HIZ

 

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

 

HFO

 

 

Register

 

 

CHFO

 

 

Register

R13

 

R13

(HFO)

 

Register

 

 

R13HIZ

 

 

HDO

 

 

Register

 

 

CHDO

 

 

Register

R12

 

R12

(HDO)

bus

Register

 

R12HIZ

 

Data

XRMUTE

 

 

 

 

Register

 

 

CRMO

 

 

Register

R11

 

R11

(XRMUTE)

 

Register

 

 

R11HIZ

 

 

XTMUTE

 

 

Register

 

 

CTMO

 

 

Register

R10

 

R10

(XTMUTE)

 

Register

 

 

R10HIZ

 

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 (VDD).

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.

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S1C63558 TECHNICAL MANUAL