MC68302EH16C Freescale Semiconductor, MC68302EH16C Datasheet - Page 90

• Manufacturer Part Number: MC68302EH16C
• Description: IC MPU MULTI-PROTOCOL 132-PQFP
• Manufacturer: Freescale Semiconductor

Specifications of MC68302EH16C

• Processor Type: M683xx 32-Bit
• Speed: 16MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 132-MQFP, 132-PQFP
• Controller Family/series: 68K
• Core Size: 32 Bit
• Ram Memory Size: 1152Byte
• Cpu Speed: 16MHz
• No. Of Timers: 3
• Embedded Interface Type: SCP, TDM
• Digital Ic Case Style: PQFP
• Rohs Compliant: Yes
• Family Name: M68000
• Device Core: ColdFire
• Device Core Size: 32b
• Frequency (max): 16MHz
• Instruction Set Architecture: RISC
• Supply Voltage 1 (typ): 5V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 132
• Package Type: PQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

System Integration Block (SIB)
REF—Output Reference Event
Bits 7–2—Reserved for future use.
3.5.2.6 General Purpose Timer Example
This section gives two examples on how to program the general purpose timers.
3.5.2.6.1 Timer Example 1
Generate an interrupt every 10 mS using the 20 MHz system clock.
Fine adjustments can be made to the timer by varying the TRR up or down.
3.5.2.6.2 Timer Example 2
Generate a 100 Hz square wave using the 20 MHz system clock. As in Timer Example 1,
the period is 10 mS, so we can use the same Prescaler and Reference values. When OM
is set, the TOUT pin only toggles when the reference value is reached. Therefore the refer-
ence value must be divided by two in order to generate two edges every 100 mS.
3-40
The counter has reached the TRR value. The ORI bit in the TMR is used to enable the
interrupt request caused by this event.
1. Take the desired interrupt period and divide by the timer clock period to get an initial
2. To calculate the value for the clock divider, divide the count by 65536 (2
3. The divider must be rounded up to the next integer value. A clock divider of 4 then
4. Program the TRR to $C350 ( = 50000 decimal).
5. Program the TMR to $031B (prescaler = 3, ORI =1 to enable interrupt, FRR = 1 to re-
1. Program the Port B control register to change the port pin from a general purpose input
2. Program the TRR to $61A8 ( = 50000/2).
3. Program the TMR to $321B (prescaler = 3, OM =1 to toggle TOUT, FRR = 1 to restart
count value to calculate prescaler.
changes the input timer period to Tin*4. A new count is calculated based on the new
timer period, and this value will be written to the TRR. The prescaler in the TMR is
equal to the clock divider minus 1 (or 4-1 = 3).
start counter after reference is reached, ICLK = 01 to use the master clock, and RST
= 1 to enabled the timer).
pin to TOUT.
Tout
------------ -
-------------------------------------
Tin Divider
Tin
Count
-----------------
65536
Tout
=
MC68302 USER’S MANUAL
------------------- -
------------------- -
20 MHz
10 ms
1
=
Divider
=
=
----------------------- -
50 ns 4
10 ms
Count
=
3.05176
=
=
200 000
50 000
,
,
16
).
MOTOROLA