mc68hc11f1cpu5 Freescale Semiconductor, Inc, mc68hc11f1cpu5 Datasheet - Page 29

• Manufacturer Part Number: mc68hc11f1cpu5
• Description: 8-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

6 Electrically Erasable Programmable ROM
6.1 EEPROM Operation
6.2 EEPROM Registers
Bits [7:5] — Not implemented. Reads always return zero and writes have no effect.
PTCON — Protect for CONFIG
BPRT[3:0] — Block Protect Bits for EEPROM
MC68HC11F1/FC0
MC68HC11FTS/D
BPROT — Block Protect
RESET
The MC68HC11F1 has 512 bytes of electrically erasable programmable ROM (EEPROM). A nonvola-
tile, EEPROM-based configuration register (CONFIG) controls whether the EEPROM is present or ab-
sent and determines its position in the memory map. In single-chip and bootstrap modes the EEPROM
is positioned at $FE00–$FFFF. In expanded and special test modes, the EEPROM can be repositioned
to any 4-Kbyte boundary ($xE00–$xFFF).
The EEON bit in CONFIG controls whether the EEPROM is present in the memory map. When
EEON = 1, the EEPROM is enabled. When EEON = 0, the EEPROM is disabled and removed from the
memory map. EEON is forced to one out of reset in single-chip and special bootstrap modes to enable
EEPROM. EEON is forced to zero out of reset in special test mode to remove EEPROM from the mem-
ory map, although test software can turn it back on. In normal expanded mode, EEON is reset to the
value last programmed into CONFIG.
An on-chip charge pump develops the high voltage required for programming and erasing. When the
E-clock frequency is 1 MHz or above, the charge pump is driven by the E-clock. When the E-clock fre-
quency is less than 1 MHz, select the internal RC oscillator to drive the EEPROM charge pump by writ-
ing one to the CSEL bit in the OPTION register. Refer to the discussion of the OPTION register in 4.3
System Initialization Registers, page 23.
0 = CONFIG register can be programmed or erased normally
1 = CONFIG register cannot be programmed or erased
0 = Protection disabled
1 = Protection enabled
Bit 7
0
0
Block protect register bits can be written to zero (protection disabled) only once
within 64 cycles of a reset in normal modes, or at any time in special modes. Block
protect register bits can be written to one (protection enabled) at any time.
Bit Name
BPRT3
BPRT2
PBRT1
BPRT0
6
0
0
Table 14 Block Protect Bits for EEPROM
EEPROM is available on the MC68HC11F1 only.
5
0
0
Block Protected
$xE60–xEDF
$xEE0–xFFF
$xE20–xE5F
$xE00–xE1F
PTCON
4
1
NOTE
NOTE
BPRT3
3
1
BPRT2
2
1
Block Size
288 Bytes
128 Bytes
64 Bytes
32 Bytes
BPRT1
1
1
BPRT0
Bit 0
1
MOTOROLA
$x035
29