
328
(2) Mode 7
In mode 7, port E functions as an I/O port, and input or output can be specified bit by bit. Setting
a PEDDR bit to 1 makes the corresponding port E pin an output port, while clearing the bit to 0
makes the pin an input port.
Port E pin functions in mode 7 are shown in figure 9-17.
PE7 (input/output)
PE6 (input/output)
PE5 (input/output)
PE4 (input/output)
PE3 (input/output)
PE2 (input/output)
PE1 (input/output)
PE0 (input/output)
Port E
Figure 9-17 Port E Pin Functions (Mode 7)
9.11.4
MOS Input Pull-Up Function
Port E has a built-in MOS input pull-up function that can be controlled by software. MOS input
pull-up can be used in modes 4 to 6 in 8-bit bus mode, or in mode 7, and can be specified as on or
off for individual bits.
With the port input pin function (modes 4 to 6 in 8-bit bus mode, or mode 7), when a PEDDR bit
is cleared to 0, setting the corresponding PEPCR bit to 1 turns on the MOS input pull-up for that
pin.
The MOS input pull-up function is in the off state after a power-on reset and in hardware standby
mode. The previous state is retained after a manual reset and in software standby mode.
Table 9-21 summarizes the MOS input pull-up states.