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(7) P60 to P65 (Port 6) ··· 3-state I/O
P60 to P65 constitute a 6-bit I/O port that can be set to input or output in 1-bit units.
P60 to P65 can also function as an address bus (A16 to A21) when memory is expanded externally. When the
port 6 is accessed in 8-bit units, the higher 2 bits of port 6 are ignored when they are written to and 00 is read
when they are read.
The I/O signal level uses the bus interface power supply pins BV
(a) Port function
P60 to P65 can be set to input or output in 1-bit units using the port 6 mode register (PM6).
(b) Alternate functions (External expansion function)
P60 to P65 can be set as A16 to A21 using the memory expansion mode register (MM).
(i)
A16 to A21 (Address bus 16 to 21) ··· output
These comprise an address bus that is used for external access. These pins operate as the higher 6-
bit address output pins within a 22-bit address. The output changes in synchronization with the rising
edge of the clock in the T1 state of the bus cycle. When the timing sets the bus cycle to inactive, the
previous bus cycle's address is retained.
(8) P70 to P77 (Port 7), P80 to P83 (Port 8) ··· input
P70 to P77 constitute an 8-bit input-only port in which all the pins are fixed to input mode. P80 to P83 constitute
a 4-bit input-only port in which all the pins are fixed to input.
P70 to P77 and P80 to P83 can also function as analog input pins for the A/D converter.
(a) Port function
P70 to P77 and P80 to P83 are input-only pins.
(b) Alternate functions
P70 to P77 also function as ANI0 to ANI7 and P80 to P83 also function as ANI8 to ANI11.
(i)
ANI0 to ANI11 (Analog input 0 to 11) ··· input
These are analog input pins for the A/D converter.
Connect a capacitor between these pins and AV
not apply voltage that is outside the range for AV
the A/D converter. If it is possible for noise above the AV
these pins using a diode that has a small V
86
CHAPTER 2
PIN FUNCTIONS
DD
to prevent noise-related operation faults. Also, do
SS
and AV
SS
value.
F
User's Manual U13850EJ6V0UD
and BV
as reference.
SS
to pins that are being used as inputs for
REF
range or below the AV
REF
to enter, clamp
SS
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