mc68hc705e5 Freescale Semiconductor, Inc, mc68hc705e5 Datasheet - Page 108

• Manufacturer Part Number: mc68hc705e5
• Description: M68hc05 Family Of Microcontrollers Mcus
• Manufacturer: Freescale Semiconductor, Inc

User EPROM
General Release Specification
Three pins are used to select various bootloader functions: PB0, PB3,
and PB4. PB0 is normally a SYNC pin, which is used to synchronize the
MCU to an off-chip source driving EPROM data into the MCU. If an
external EPROM is used, this pin must be connected to V
PB3 are used to select a programming mode. Two other pins, PC2 and
PC3, are used to drive the PROG LED and the VERF LED, respectively.
The programming modes along with gate and drain stress are shown in
Table
The bootloader uses an external 12-bit counter to address the memory
device containing the code to be copied. This counter requires a clock
and a reset function. The 12-bit counter can address up to 4 Kbytes of
memory, which means that a port pin has to be used to address the extra
memory space.
Freescale Semiconductor, Inc.
For More Information On This Product,
13-1.
SYNC
SYNC
SYNC
PB0
0
1
Go to: www.freescale.com
Table 13-1. Bootloader Functions
User EPROM
PB4
1
1
0
0
0
PB3
1
0
0
1
1
Program/Verify
Factory Test
Factory Test
Factory Test
Verify Only
MC68HC705E5
Mode
SS
. PB4 and
—
Rev. 1.0