mc68hc705j2 Freescale Semiconductor, Inc, mc68hc705j2 Datasheet - Page 63

• Manufacturer Part Number: mc68hc705j2
• Description: 8-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

8.1 Bootloader ROM
8.1.1 External EPROM Downloading
MC68HC705J2
This section describes how to use the bootloader ROM to download to the
on-chip EPROM.
The bootloader ROM, located at addresses $0F01–$0FEF, contains routines for
copying to the on-chip EPROM from an external EPROM or from a personal
computer.
In MC68HC705J2 native mode, the bootloader copies to the 2 Kbyte space
located at EPROM addresses $0700–$0EFF.
mode, the bootloader copies to the 1 Kbyte space located at EPROM addresses
$0300–$06FF.
internal addresses to which the code is copied.
other addresses.
The COP timer is automatically disabled in bootloader mode.
Figure 8-1 shows the circuit used to download to the on-chip EPROM from a
2764 EPROM. The bootloader circuit includes an external 12-bit counter to
address the EPROM containing the code to be copied.
Operation is fastest when unused external EPROM addresses contain $00.
The addresses of the copied code must correspond to the
BOOTLOADER MODE
BOOTLOADER MODE
SECTION 8
In MC68HC05J1 emulation
The bootloader ignores all
MOTOROLA
8-1