mc68hc05x4dw Freescale Semiconductor, Inc, mc68hc05x4dw Datasheet - Page 19

• Manufacturer Part Number: mc68hc05x4dw
• Description: Xc68hc705x4 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

EPROM
programming
register
7-modes
NOTE:
Address:
EPROM containing the user code are incremented independently it is
essential that the data layout in the 2764 EPROM conforms exactly to
the MC68HC705X4 memory map.
The bootloader uses an external 12-bit counter with a clock and a reset
function to address the memory device containing the code to be copied.
The 12-bit counter can address up to 4K bytes of memory therefore a
port pin must be used to address the additional memory space.
In bootloader mode the device will always default to the divide-by-10
option for the oscillator division ratio.
All necessary manipulation of this register is carried out automatically by
the bootloader routine.
ELAT — EPROM address and data latch
EPGM — EPROM programming power control
A byte of EPROM is programmed using the following sequence:
Reset:
Freescale Semiconductor, Inc.
For More Information On This Product,
1 = Configures EPROM address and data buses for programming.
0 = Configures EPROM address and data buses for normal
1 = Switches EPROM programming power on.
0 = Switches EPROM programming power off.
– set ELAT
– write data to the desired EPROM address
– set EPGM for time t
– clear EPGM/ELAT
Modes of Operation and Pin Descriptions
Figure 3. EPROM Programming Register (EPROG)
$1G00
Bit 7
operation.
0
0
Go to: www.freescale.com
6
0
0
Bootloader modes for the MC68HC05X4 and MC68HC705X4
5
0
0
PROG
4
0
0
Modes of Operation and Pin Descriptions
3
0
0
ELAT
2
0
MC68HC05X4 Rev 1.0
1
0
0
EPGM
Bit 0
0