MC68HC05J3 Datasheet, PDF (17/92 Pages) Motorola, Inc – High-density Complementary Metal Oxide Semiconductor (HCMOS) Microcomputer Unit

2
2
MODES OF OPERATION AND
PIN DESCRIPTIONS
2.1
Modes of operation
The MC68HC05J3 has two modes of operation, single chip and RAM bootloader mode. Table 2-1
shows the conditions required to enter each mode on the rising edge of RESET.
Table 2-1 MC68HC05J3 operating mode entry conditions
RESET IRQ TCAP PA3
V_SS to V_DD x
1
1.8 V_DD
1
x Single chip
0
RAM bootloader
1
x = don’t care
Mode
Jump to RAM ($0081)
Load RAM & execute ($0081)
2.1.1 Single chip mode
This is the normal operating mode of the MC68HC05J3. In this mode the device functions as a
self-contained microcomputer (MCU) with all on-board peripherals, including the 8-bit I/O port (A)
and the 6-bit I/O port (B), available to the user. All address and data activity occurs within the MCU.
Single chip mode is entered on the rising edge of RESET if the voltage level on the IRQ pin is
within the normal operating range.
MC68HC05J3
MODES OF OPERATION AND PIN DESCRIPTIONS
TPG
MOTOROLA
2-1