NEC Renesas V850/SC1 User Manual page 74

(7) P60 to P65 (port 6) ··· 3-state I/O
P60 to P65 function as a 6-bit I/O port in which input and output can be specified in 1-bit units.
In addition to I/O port pins, these pins can also be used as an address bus (A16 to A21) when memory is
expanded externally. During 8-bit access of port 6, the higher two bits are ignored during a write operation and
are read as "00" during a read operation.
(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 function (external expansion mode)
P60 to P65 can be specified as A16 to A21 using the memory expansion mode register (MM).
(i) A16 to A21 (address 16 to 21) ··· Output
These pins comprise an address bus 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, these pins
hold the address of the bus cycle immediately before.
(8) P70 to P77 (port 7), P80 to P83 (port 8) ··· Input
P70 to P77 function as an 8-bit input-only port in which all pins are fixed as input pins. P80 to P83 function as a
4-bit input-only port in which all pins are fixed as input pins.
In addition to input ports, these pins can also be used as analog input pins of the A/D converter for the alternate
function. However, they cannot be switched between input ports and analog input pins.
(a) Port function
P70 to P77 and P80 to P83 are input-only pins.
(b) Alternate function
P70 to P77 also function as pins ANI0 to ANI7 and P80 to P83 also function as ANI8 to ANI11, but these
alternate functions are not switchable.
(i) ANI0 to ANI11 (analog input 0 to 11) ··· Input
These are analog input pins for the A/D converter.
Connect a capacitor between ADCV
not apply voltage that is outside the range for ADCV
inputs for the A/D converter. If it is possible for noise above the ADCV
range to enter, clamp these pins using a diode that has a small V
72
CHAPTER 2 PIN FUNCTIONS
and ADCGND to prevent noise-related operation faults. Also, do
DD
DD
User's Manual U15109EJ3V0UD
and ADCGND to pins that are being used as
range or below the ADCGND
DD
value.
F