mc68hc11ea9 Freescale Semiconductor, Inc, mc68hc11ea9 Datasheet - Page 21

• Manufacturer Part Number: mc68hc11ea9
• Description: 8-bit Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

CONFIG — Security, COP, ROM/EPROM, and EEPROM Enables
Bits [7:4] — Not Implemented
NOSEC — Security Disable
NOCOP — COP System Disable
ROMON — ROM/EPROM/OTPROM Enable
EEON — EEPROM Enable
4.10.3 EEPROM Security
MC68HC11EA9
MC68HC11EA9TS/D
RESETS:
S. Chip:
Boot:
Exp.:
Test:
U indicates a previously programmed bit. U(L) indicates that the bit resets to the logic level held in the
latch prior to reset (unchanged), but the function of COP is controlled by DISR bit in TEST1 register.
Always read zero
NOSEC is invalid unless the security mask option is specified before the MCU is manufactured. If se-
curity mask option is omitted NOSEC always reads one. The security feature protects the contents of
RAM and EEPROM.
Refer to 5 Resets and Interrupts.
When this bit is zero, the ROM or EPROM/OTPROM is disabled and that memory space becomes ex-
ternally addressed. In single-chip mode, ROMON is forced to one to enable ROM/EPROM/OTPROM
regardless of the state of the ROMON bit.
When this bit is zero, the EEPROM is disabled and that memory space becomes externally addressed.
The optional security feature, available only on ROM-based MCUs, protects the EEPROM and RAM
contents from unauthorized access. A program, or a key portion of a program, can be protected against
unauthorized duplication. To accomplish this, the protection mechanism restricts operation of protected
devices to the single-chip modes. This prevents the memory locations from being monitored externally
because single-chip modes do not allow visibility of the internal address and data buses. Resident pro-
grams, however, have unlimited access to the internal EEPROM and RAM and can read, write, or trans-
fer the contents of these memories.
0 = Security enabled
1 = Security disabled
0 = ROM/EPROM/OTPROM disabled from the memory map
1 = ROM/EPROM/OTPROM present in the memory map
0 = EEPROM removed from the memory map
1 = EEPROM present in the memory map
BIT 7
—
0
0
0
0
—
6
0
0
0
0
Freescale Semiconductor, Inc.
For More Information On This Product,
—
5
0
0
0
0
Go to: www.freescale.com
—
4
0
0
0
0
NOSEC
U
U
3
1
1
NOCOP
U(L)
U(L)
U
U
2
ROMON
U
U
U
1
1
EEON
BIT 0
U
U
U
U
$103F
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