mc68hc08ln56 Freescale Semiconductor, Inc, mc68hc08ln56 Datasheet - Page 215

• Manufacturer Part Number: mc68hc08ln56
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Chapter 18
EPROM/OTPROM
18.1 Introduction
This section describes the non-volatile memory (EPROM/OTPROM).
18.2 Functional Description
An MCU with a quartz window has 56 Kbytes of erasable, programmable ROM (EPROM). The quartz
window allows EPROM erasure by using ultraviolet light. In an MCU without the quartz window, the
EPROM cannot be erased and serves as 56 Kbytes of one-time programmable ROM (OTPROM). An
unprogrammed or erased location reads as $00. Hardware interlocks are provided to protect stored data
corruption from accidental programming. These addresses are user EPROM/OTPROM locations:
Programming tools are available from Freescale. Contact your local Freescale representative for more
information.
18.3 EPROM/OTPROM Control Registers (EPMCR1, EPMCR2)
The EPROM control registers control EPROM/OTPROM programming.
1. No security feature is absolutely secure. However, Freescale’s strategy is to make reading or copying the EPROM/OTPROM
Freescale Semiconductor
difficult for unauthorized users.
•
•
$1E00:$FDFF
$FFD8:$FFFF (These locations are reserved for user-defined interrupt and reset vectors.)
EPMCR1
EPMCR2
$FE07
$FE08
Reset:
Reset:
Read:
Read:
Write:
Write:
If the security feature is enabled, viewing of the EPROM/OTPROM
contents is prevented.
Figure 18-1. EPROM/OTPROM Control Registers (EPMCR1, EPMCR2)
MC68HC08LN56 • MC68HC708LN56 General Release Specification, Rev. 2.1
Bit 7
Bit 7
R
R
0
0
= Unimplemented
R
R
6
0
6
0
(1)
R
R
5
0
5
0
NOTE
R
R
4
0
4
0
R
R
R
3
0
3
0
= Reserved
ELAT1
ELAT2
2
0
2
0
R
R
1
0
1
0
EPGM1
EPGM2
Bit 0
Bit 0
0
0
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