MC68HC908GP16CFB Freescale Semiconductor, MC68HC908GP16CFB Datasheet - Page 41

• Manufacturer Part Number: MC68HC908GP16CFB
• Description: MCU 8-BIT 16K FLASH 44-QFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908GP16CFB

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 33
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

2.6.5 FLASH Block Protection
Due to the ability of the on-board charge pump to erase and program the FLASH memory in the target
application, provision is made for protecting a block of memory from unintentional erase or program
operations due to system malfunction. This protection is done by using the FLASH block protect register
(FLBPR). The FLBPR determines the range of the FLASH memory which is to be protected. The range
of the protected area starts from a location defined by FLBPR and ends at the bottom of the FLASH
memory ($FFFF). When the memory is protected, the HVEN bit cannot be set in either erase or program
operations.
When FLBPR is programmed with all 0s, the entire memory is protected from being programmed and
erased. When all the bits are erased (all 1s), the entire memory is accessible for program and erase.
When bits within the FLBPR are programmed, they lock a block of memory address ranges as shown in
2.6.6 FLASH Block Protect
any erase or program of the FLBPR or the protected block of FLASH memory is prohibited. Mass erase
is disabled whenever any block is protected (FLBPR does not equal $FF). The presence of a V
IRQ pin will bypass the block protection so that all of the memory included in the block protect register is
open for program and erase operations.
2.6.6 FLASH Block Protect Register
The FLASH block protect register (FLBPR) is implemented as a byte within the FLASH memory, and
therefore can be written only during a programming sequence of the FLASH memory. The value in this
register determines the starting location of the protected range within the FLASH memory.
BPR7–BPR0 — FLASH Block Protect Bits
Freescale Semiconductor
These eight bits represent bits [13:6] of a 16-bit memory address. Bit 15 and Bit 14 are 1s and bits [5:0]
are 0s.
The resultant 16-bit address is used for specifying the start address of the FLASH memory for block
protection. The FLASH is protected from this start address to the end of FLASH memory, at $FFFF.
With this mechanism, the protect start address can be $XX00, $XX40, $XX80, and $XXC0 (64 bytes
page boundaries) within the FLASH memory.
Address:
In performing a program or erase operation, FLBPR must be read after
setting the PGM or ERASE bit and before asserting the HVEN bit.
Reset:
Read:
Write:
START ADDRESS OF FLASH
Write to this register is by a programming sequence to the FLASH memory.
$FF7E
BPR7
Bit 7
Figure 2-5. FLASH Block Protect Register (FLBPR)
Figure 2-6. FLASH Block Protect Start Address
Register. Once the FLBPR is programmed with a value other than $FF or $FE,
BLOCK PROTECT
MC68HC908EY16 • MC68HC908EY8 Data Sheet, Rev. 10
BPR6
6
Unaffected by reset. Initial value from factory is $FF.
1
BPR5
5
1
NOTE
BPR4
FLBPR VALUE
4
16-BIT MEMORY ADDRESS
BPR3
3
BPR2
0 0 0 0 0 0
2
BPR1
1
FLASH Memory (FLASH)
BPR0
Bit 0
TST
on the
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