MCF51EM256CLL Freescale Semiconductor, MCF51EM256CLL Datasheet - Page 84

• Manufacturer Part Number: MCF51EM256CLL
• Description: IC MCU 32BIT 256KB FLASH 100LQFP
• Manufacturer: Freescale Semiconductor
• Series: MCF51EMr

Specifications of MCF51EM256CLL

• Core Processor: Coldfire V1
• Core Size: 32-Bit
• Speed: 50MHz
• Connectivity: I²C, SCI, SPI
• Peripherals: LCD, LVD, PWM, WDT
• Number Of I /o: 63
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Data Converters: A/D 16x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-LQFP
• Processor Series: MCF51EM
• Core: ColdFire V1
• Data Bus Width: 32 bit
• Data Ram Size: 16 KB
• Interface Type: RS-232, LIN
• Maximum Clock Frequency: 50 MHz
• Number Of Timers: 3
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JLINK-CF-BDM26, EWCF
• Development Tools By Supplier: DEMOEM
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Memory
3.3
An MCF51EM256 series microcontroller includes up to 16 KB of static RAM. RAM is most efficiently
accessed using the A5-relative addressing mode (address register indirect with displacement mode). Any
single bit in this area can be accessed with the bit manipulation instructions (BCLR, BSET,etc.).
At power-on, the contents of RAM are uninitialized. RAM data is unaffected by any reset provided that
the supply voltage does not drop below the minimum value for RAM retention (V
3.4
The flash memory is for program storage and read-only data. In-circuit programming allows the operating
program to be loaded into the flash memory after final assembly of the application product. It is possible
to program the entire array through the single-wire background debug interface. Because no special
voltages are needed for flash erase and programming operations, in-application programming is also
possible through other software-controlled communication paths.
Flash memory is ideal for single-supply applications allowing for field reprogramming without requiring
external high voltage sources for program or erase operations. The flash module includes a memory
controller that executes commands to modify flash memory contents.
Array read access time is one bus cycle for bytes, aligned words, and aligned longwords. Multiple accesses
are needed for misaligned words and longword operands. For flash memory, an erased bit reads 1 and a
programmed bit reads 0. It is not possible to read from a flash block while any command is executing on
that specific flash block.
Flash memory on this device must be programmed 32-bits at a time with long word address aligned when
the low-voltage detect flag (LVDF) in the system power management status and control 1 register
(SPMSC1) is clear. If SPMSC1[LVDF] is set, the programming sequence must be modified such that odd
and even bytes are written separately. This device’s flash memory is organized as two 16-bit wide blocks
interleaved to yield a 32-bit data path. When programming flash if LVDF is set, alternate bytes must be set
to 0xFF as shown in
flash array.
3-28
RAM
Flash Memory
A flash block address must be in the erased state before being programmed.
Cumulative programming of bits within a flash block address is not allowed
except for status field updates required in EEPROM emulation applications.
MCF51EM256 Series ColdFire Integrated Microcontroller Reference Manual, Rev. 8
Table
0x00 – 0x03
0x00 – 0x03
0x04 – 0x07
0x04 – 0x07
Addresses
3-5. Failure to adhere to these guidelines may result in a partially programmed
Table 3-5. Alternate Bytes Setting
0xCCCC_CCCC
Desired Value
0x5555_AAAA
CAUTION
Values Programmed
0xCCFF_CCFF
0xFFCC_FFCC
0x55FF_AAFF
0xFF55_FFAA
RAM
Freescale Semiconductor
).