MC68HC705P6A Datasheet, PDF (36/130 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Operating Modes
The mode of operation is also determined whenever the internal
computer operating properly (COP) watchdog timer resets the MCU.
When the COP timer expires, the voltage applied to the IRQ/V_PP pin
controls the mode of operation while the voltage applied to PD7/TCAP is
ignored. The voltage applied to PD7/TCAP during the last rising edge on
RESET is stored in a latch and used to determine the mode of operation
when the COP watchdog timer resets the MCU.
3.3 User Mode
The user mode allows the MCU to function as a self-contained
microcontroller, with maximum use of the pins for on-chip peripheral
functions. All address and data activity occurs within the MCU and are
not available externally. User mode is entered on the rising edge of
RESET if the IRQ/V_PP pin is within the normal operating voltage range.
The pinout for the user mode is shown in Figure 3-1.
RESET
1
IRQ/V_PP
2
PA7
3
PA6
4
PA5
5
PA4
6
PA3
7
PA2
8
PA1
9
PA0
10
SDO/PB5
11
SDI/PB6
12
SCK/PB7
13
V_SS
14
28
V_DD
27
OSC1
26
OSC2
25
PD7/TCAP
24
TCMP
23
PD5
22
PC0
21
PC1
20
PC2
19
PC3/AD3
18
PC4/AD2
17
PC5/AD1
16
PC6/AD0
15
PC7/V_REFH
Figure 3-1. User Mode Pinout
In the user mode, there is an 8-bit I/O port, a second 8-bit I/O port shared
with the analog-to-digital (A/D) subsystem, one 3-bit I/O port shared with
the serial input/output port (SIOP), and a 3-bit port shared with the 16-bit
timer subsystem, which includes one general-purpose I/O pin.
Advance Information
36
Operating Modes
MC68HC705P6A — Rev. 2.0
MOTOROLA