Datasheet
Table Of Contents
- Part 1 Overview
- Part 2 Signal/Connection Descriptions
- 2.1 Introduction
- 2.2 Power and Ground Signals
- 2.3 Clock and Phase Locked Loop Signals
- 2.4 Address, Data, and Bus Control Signals
- 2.5 Interrupt and Program Control Signals
- 2.6 GPIO Signals
- 2.7 Pulse Width Modulator (PWM) Signals
- 2.8 Serial Peripheral Interface (SPI) Signals
- 2.9 Quadrature Decoder Signals
- 2.10 Serial Communications Interface (SCI) Signals
- 2.11 CAN Signals
- 2.12 Analog-to-Digital Converter (ADC) Signals
- 2.13 Quad Timer Module Signals
- 2.14 JTAG/OnCE
- Part 3 Specifications
- 3.1 General Characteristics
- 3.2 DC Electrical Characteristics
- 3.3 AC Electrical Characteristics
- 3.4 Flash Memory Characteristics
- 3.5 External Clock Operation
- 3.6 External Bus Asynchronous Timing
- 3.7 Reset, Stop, Wait, Mode Select, and Interrupt Timing
- 3.8 Serial Peripheral Interface (SPI) Timing
- 3.9 Quad Timer Timing
- 3.10 Quadrature Decoder Timing
- 3.11 Serial Communication Interface (SCI) Timing
- 3.12 Analog-to-Digital Converter (ADC) Characteristics
- 3.13 Controller Area Network (CAN) Timing
- 3.14 JTAG Timing
- Part 4 Packaging
- Part 5 Design Considerations
- Part 6 Ordering Information
56F805 Technical Data, Rev. 16
28 Freescale Semiconductor
Figure 3-6 Flash Mass Erase Cycle
3.5 External Clock Operation
The 56F805 system clock can be derived from a crystal or an external system clock signal. To generate a
reference frequency using the internal oscillator, a reference crystal must be connected between the
EXTAL and XTAL pins.
3.5.1 Crystal Oscillator
The internal oscillator is also designed to interface with a parallel-resonant crystal resonator in the
frequency range specified for the external crystal in Table 3-9. In Figure 3-7 a recommended crystal
oscillator circuit is shown. Follow the crystal supplier’s recommendations when selecting a crystal,
because crystal parameters determine the component values required to provide maximum stability and
reliable start-up. The crystal and associated components should be mounted as close as possible to the
EXTAL and XTAL pins to minimize output distortion and start-up stabilization time. The internal 56F80x
oscillator circuitry is designed to have no external load capacitors present. As shown in Figure 3-8, no
external load capacitors should be used.
The 56F80x components internally are modeled as a parallel resonant oscillator circuit to provide a
capacitive load on each of the oscillator pins (XTAL and EXTAL) of 10pF to 13pF over temperature and
process variations. Using a typical value of internal capacitance on these pins of 12pF and a value of 3pF
XADR
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ERASE
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Tnvs
Tnvh1
Trcv
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MAS1
IFREN
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