MCF51EM256CLL Freescale Semiconductor, MCF51EM256CLL Datasheet - Page 371

• 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

16.3.2
The two read-only TPM counter registers contain the high and low bytes of the value in the TPM counter.
Reading either byte (TPMCNTH or TPMCNTL) latches the contents of both bytes into a buffer where they
remain latched until the other half is read. This allows coherent 16-bit reads in either big-endian or
little-endian order which makes this more friendly to various compiler implementations. The coherency
mechanism is automatically restarted by an MCU reset or any write to the timer status/control register
(TPMSC).
Reset clears the TPM counter registers. Writing any value to TPMCNTH or TPMCNTL also clears the
TPM counter (TPMCNTH:TPMCNTL) and resets the coherency mechanism, regardless of the data
involved in the write.
Freescale Semiconductor
Reset
W
R
Bit 15
TPM-Counter Registers (TPMCNTH:TPMCNTL)
0
7
MCF51EM256 Series ColdFire Integrated Microcontroller Reference Manual, Rev. 8
14
0
6
Figure 16-7. TPM Counter Register High (TPMCNTH)
CLKS
000
001
010
011
100
101
110
111
Table 16-3. TPM-Clock-Source Selection
PS
00
01
10
11
Table 16-4. Prescale Factor Selection
Any write to TPMCNTH clears the 16-bit counter
13
5
0
No clock selected (TPM counter disable)
TPM Clock Source to Prescaler Input
TPM Clock Source Divided-by
12
0
4
Fixed system clock
External source
Bus rate clock
128
16
32
64
1
2
4
8
11
0
3
10
0
2
Timer/PWM Module(TPM)
1
9
0
Bit 8
0
0
16-9