MCF51EM256CLL Freescale Semiconductor, MCF51EM256CLL Datasheet - Page 536

• 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

LCD Driver Module
SOURCE
BRATE[2:0]
LCLK[2:0]
÷(2
12+BRATE[2:0]
Blink Frequency
)
Alternate Clock
LCDCLK
÷4
÷ 2 x (4+LCLK[2:0]) x Y)
OSCOUT = 32.768 kHz
÷6∗(2
LADJ[1:0]
)
LCD Base Clock
÷ (DUTY+1)
Blink Rate
LCD Charge Pump Clock
Source
LADJ[1:0]
LCD Frame Frequency
Figure 24-11. LCD Clock Tree
An external 32.768 kHz clock input is required to achieve lowest power consumption.
The value of LCDCLK is important because it is used to generate the LCD module frame frequency.
Equation 24-1
provides an expression for the LCD module frame frequency calculation.
The LCD module frame frequency is a function of the LCD module duty cycle as shown in
Equation
24-1.
Table 24-16
and
Table 24-15
show LCD module frame frequency calculations that consider several
possible LCD module configurations of LCLK[2:0] and DUTY[2:0].
The LCD module frame frequency is defined as the number of times the LCD segments are energized per
second. The LCD module frame frequency must be selected to prevent the LCD display from flickering
(LCD module frame frequency is too low) or ghosting (LCD module frame frequency is too high). To
avoid these issues, an LCD module frame frequency in the range of 28 to 58 Hz is required. LCD module
frame frequencies less than 28 Hz or greater than 58 Hz are out of specification, and so are invalid.
Selecting lower values for the LCD base and frame frequency results in lower current consumption for the
LCD module.
The LCD module base clock frequency is the LCD module frame frequency multiplied by the number of
backplane phases that are being generated. The number of backplane phases is selected using the
DUTY[2:0] bits. The LCD module base clock is used by the backplane sequencer to generate the LCD
waveform data for the enabled phases (A-H).
MCF51EM256 Series ColdFire Integrated Microcontroller Reference Manual, Rev. 8
24-20
Freescale Semiconductor