MC68340AG16VE Freescale Semiconductor, MC68340AG16VE Datasheet - Page 106

• Manufacturer Part Number: MC68340AG16VE
• Description: IC MPU 32BIT 16MHZ 144-LQFP
• Manufacturer: Freescale Semiconductor

Specifications of MC68340AG16VE

• Processor Type: M683xx 32-Bit
• Speed: 16MHz
• Voltage: 3.3V
• Mounting Type: Surface Mount
• Package / Case: 144-LQFP
• Controller Family/series: 68K
• Core Size: 32 Bit
• No. Of I/o's: 16
• Cpu Speed: 16MHz
• No. Of Timers: 2
• Embedded Interface Type: UART
• Digital Ic Case Style: LQFP
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

4.2.2.6.2 Using the Periodic Timer as a Real-Time Clock. The periodic interrupt timer
can be used as a real-time clock interrupt by setting it up to generate an interrupt with a
one-second period. Rearranging the periodic timer period equation to solve for the desired
count value:
Therefore, when using a 32.768-kHz crystal, the PITR should be loaded with a value of
$10 with the prescaler enabled to generate interrupts at a one-second rate.
4.2.2.7 SIMULTANEOUS INTERRUPTS BY SOURCES IN THE SIM40. If multiple
interrupt sources at the same interrupt level are simultaneously asserted in the SIM40, it
will prioritize and service the interrupts in the following order: 1) software watchdog, 2)
periodic interrupt timer, and 3) external interrupts.
4.2.3 Clock Synthesizer Operation
The clock synthesizer can operate with either an external crystal or an external oscillator
for reference, using the internal phase-locked loop (PLL) and voltage-controlled oscillator
(VCO), or an external clock can directly drive the clock signal at the operating frequency.
The four modes of clock operation are listed in Table 4-1.
In crystal mode (see Figure 4-4), the clock synthesizer can operate from the on-chip PLL
and VCO, using a parallel resonant crystal connected between the EXTAL and XTAL pins,
or an external oscillator connected to EXTAL as a reference frequency source. The
oscillator circuit is shown in Figure 4-5. A 32.768-kHz watch crystal provides an
inexpensive reference, but the reference crystal or external oscillator frequency can be
any frequency in the range specified in Section 11 Electrical Characteristics. When
MOTOROLA
Crystal Mode
External Clock
Mode without PLL
External Clock
Mode with PLL
Limp Mode
Mode
External crystal or oscillator used with the on-chip PLL and VCO to
generate a system clock and CLKOUT of programmable rates.
The desired operating frequency is driven into EXTAL resulting in a
system clock and CLKOUT of the same frequency, not tightly coupled.
The desired operating frequency is driven into EXTAL, resulting in a
system clock and CLKOUT of the same frequency, with a tight skew
between input and output signals.
Upon input signal loss for either clock mode using the PLL, operation
continues at approximately one-half operating speed (affected by the
value of the X-bit in the SYNCR).
PITR count value
PITR count value
PITR count value
Freescale Semiconductor, Inc.
For More Information On This Product,
Table 4-1. Clock Operating Modes
MC68340 USER’S MANUAL
Go to: www.freescale.com
=
=
=
Description
16 (decimal)
(PIT period) (EXTAL frequency)
(Prescaler value) (2 2 )
(1) (32768)
(512) (2 2 )
MODCK
Reset
Value
5 V
0 V
0 V
X
Operating
V
Value
CCSYN
5 V
0 V
5 V
5 V
4- 9