Port 11; Block Diagram Of P110 To P117 - NEC mPD780208 Subseries User Manual

4.2.9 Port 11

Port 11 is an 8-bit I/O port with an output latch. The P110 to P117 pins can be set to input mode/output mode
in 1-bit units using port mode register 11 (PM11). In mask ROM versions, use of pull-down resistors can be specified
in 1-bit units with the mask option. Pull-down resistor connection to V
The µ PD78P0208 does not contain pull-down resistors.
Port 11 can drive LEDs directly.
Alternate functions include VFD controller/driver display output.
RESET input sets port 11 to input mode.
Figure 4-12 shows a block diagram of port 11.
Caution Adjust the number of pull-down resistors so that the total power dissipation (refer to 15.10
Calculating Total Power Dissipation) is not exceeded.
RD
WR
PORT
WR
PM
PM: Port mode register
RD: Port 11 read signal
WR: Port 11 write signal
CHAPTER 4 PORT FUNCTIONS
Figure 4-12. Block Diagram of P110 to P117
Selector
Output latch
(P110 to P117)
PM110 to PM117
Alternate function
User's Manual U11302EJ4V0UM
or V can be specified in 4-bit units.
LOAD SS
Mask option
Only mask ROM
versions. The
µ
PD78P0208 has no
pull-down resistors.
P110/FIP37
to
P117/FIP44
V
LOAD
93