MC68HC705JD FREESCALE [Freescale Semiconductor, Inc], MC68HC705JD Datasheet - Page 47

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MC68HC705JD

Manufacturer Part Number
MC68HC705JD
Description
member of the low-cost
Manufacturer
FREESCALE [Freescale Semiconductor, Inc]
Datasheet
8.1 Bootloader ROM
8.1.1 External EPROM Downloading
Rev. 2
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, the MOR byte at location $0F00, and the user
vector addresses $0FF0–$0FFF. In MC68HC05J1 emulation mode, the bootloader
copies to the 1 Kbyte space located at EPROM addresses $0300–$06FF, the MOR
byte at location $0700, and the user vector addresses $07F0–$07FF. The addresses
of the copied code must correspond to the internal addresses to which the code is
copied. The bootloader ignores all other addresses.
The COP timer is automatically disabled in bootloader mode.
Figure 8-1
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.
shows the circuit used to download to the on-chip EPROM from a 2764
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
BOOTLOADER MODE
BOOTLOADER MODE
SECTION 8
8-1
10
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12
13
14
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1
2
3
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