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(7) P60 to P67 (Port 6) ··· 3-state I/O
Port 6 is an 8-bit input/output port that can be set to input or output in 1-bit units.
Besides functioning as a port, in the control mode (external expansion mode) it operates as an address bus
(A16 to A23) when memory is externally expanded.
The operation mode can be set as port or control in 2-bit units, specified by the mode specification pins
(MODE0 to MODE3) and the memory expansion mode register (MM).
(a) Port mode
P60 to P67 can be set to input or output in bit units by the port 6 mode register (PM6).
(b) Control mode (External expansion mode)
P60 to P67 can be set as A16 to A23 by using the MODE0 to MODE3 pins and MM register.
(i)
A16 to A23 (Address) ··· output
These pins constitute the higher 8-bits of a 24-bits address bus when the external memory is
accessed. The output changes in synchronization with the falling edge of the CLKOUT signal in the
T1 state of the bus cycle. In the idle state (TI), the previous bus cycle's address is held.
(8) P70 to P77 (Port 7) ··· input
Port 7 is an 8-bit input-only port in which all pins are fixed as input pins.
Besides functioning as a port, in the control mode it operates as analog input for the A/D converter. However,
the input port and analog input pin cannot be switched.
(a) Port mode
P70 to P77 are input-only pins.
(b) Control mode
P70 to P77 function alternately pins ANI0 to ANI7, but these alternate functions are not switchable.
(i)
ANI0 to ANI7 (Analog Input) ··· 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
for the A/D converter. If it is possible for noise above the AV
clamp these pins using a diode that has a small V
54
CHAPTER 2 PIN FUNCTIONS
to prevent noise-related operation faults. Also, do
SS
and AV
SS
value.
F
User's Manual U12688EJ4V0UM00
to pins that are being used as inputs
REF
range or below the AV
REF
to enter,
SS
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