MC68HC711E9VFN2 Freescale Semiconductor, MC68HC711E9VFN2 Datasheet - Page 178

• Manufacturer Part Number: MC68HC711E9VFN2
• Description: IC MCU 12K OTP 2MHZ 52-PLCC
• Manufacturer: Freescale Semiconductor
• Series: HC11r

Specifications of MC68HC711E9VFN2

• Core Processor: HC11
• Core Size: 8-Bit
• Speed: 2MHz
• Connectivity: SCI, SPI
• Peripherals: POR, WDT
• Number Of I /o: 38
• Program Memory Size: 12KB (12K x 8)
• Program Memory Type: OTP
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 52-PLCC
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Timing System
9.2 Introduction
Technical Data
178
The M68HC11 timing system is composed of five clock divider chains.
The main clock divider chain includes a 16-bit free-running counter,
which is driven by a programmable prescaler. The main timer’s
programmable prescaler provides one of the four clocking rates to drive
the 16-bit counter. Two prescaler control bits select the prescale rate.
The prescaler output divides the system clock by 1, 4, 8, or 16. Taps off
of this main clocking chain drive circuitry that generates the slower
clocks used by the pulse accumulator, the real-time interrupt (RTI), and
the computer operating properly (COP) watchdog subsystems, also
described in this section. Refer to
All main timer system activities are referenced to this free-running
counter. The counter begins incrementing from $0000 as the MCU
comes out of reset and continues to the maximum count, $FFFF. At the
maximum count, the counter rolls over to $0000, sets an overflow flag,
and continues to increment. As long as the MCU is running in a normal
operating mode, there is no way to reset, change, or interrupt the
counting. The capture/compare subsystem features three input capture
channels, four output compare channels, and one channel that can be
selected to perform either input capture or output compare. Each of the
three input capture functions has its own 16-bit input capture register
(time capture latch) and each of the output compare functions has its
own 16-bit compare register. All timer functions, including the timer
overflow and RTI, have their own interrupt controls and separate
interrupt vectors.
The pulse accumulator contains an 8-bit counter and edge select logic.
The pulse accumulator can operate in either event counting mode or
gated time accumulation mode. During event counting mode, the pulse
accumulator’s 8-bit counter increments when a specified edge is
detected on an input signal. During gated time accumulation mode, an
internal clock source increments the 8-bit counter while an input signal
has a predetermined logic level.
The real-time interrupt (RTI) is a programmable periodic interrupt circuit
that permits pacing the execution of software routines by selecting one
of four interrupt rates.
Timing System
Figure
9-1.
M68HC11E Family — Rev. 3.2
MOTOROLA