Freescale Semiconductor MC68HC08KH12 , 14.4 Functional Description

Advance Information MC68HC(7)08KH12 — Rev. 1.1

214 Freescale Semiconductor

14.4 Functional Description

A logic zero applied to the external interrupt pin can latch a CPU interrupt

request. Figure 14-1 shows the structure of the IRQ module.

Interrupt signals on the IRQ1/VPP pin are latched into the IRQ1 latch. An

interrupt latch remains set until one of the following actions occurs:

• Vector fetch — A vector fetch automatically generates an interrupt

acknowledge signal that clears the IRQ latch.

• Software clear — Software can clear the interrupt latch by writing

to the acknowledge bit in the interrupt status and control register

(ISCR). Writing a logic one to the ACK1 bit clears the IRQ1 latch.

• Reset — A reset automatically clears the interrupt latch.

The external interrupt pin is falling-edge-triggered and is software-

configurable to be either falling-edge or low-level-triggered. The MODE1

bit in the ISCR controls the triggering sensitivity of the IRQ1/VPP pin.

When the interrupt pin is edge-triggered only, the CPU interrupt request

remains set until a vector fetch, software clear, or reset occurs.

When the interrupt pin is both falling-edge and low-level-triggered, the

CPU interrupt request remains set until both of the following occur:

• Vector fetch or software clear

• Return of the interrupt pin to logic one

The vector fetch or software clear may occur before or after the interrupt

pin returns to logic one. As long as the pin is low, the interrupt request

remains pending. A reset will clear the latch and the MODE1 control bit,

thereby clearing the interrupt even if the pin stays low.

When set, the IMASK1 bit in the ISCR mask all external interrupt

requests. A latched interrupt request is not presented to the interrupt

priority logic unless the IMASK1 bit is clear.

NOTE: The interrupt mask (I) in the condition code register (CCR) masks all

interrupt requests, including external interrupt requests.(See 7.6

Exception Control.)

Contents

Main Page List of Sections Page Table of Contents General Description Section 2. Memory Map Section 3. Random-Access Memory (RAM) Section 4. Read-Only Memory (ROM) Section 5. Configuration Register (CONFIG) Section 6. Central Processor Unit (CPU) Section 7. System Integration Module (SIM) Section 8. Clock Generator Module (CGM) Section 9. Universal Serial Bus Module (USB) Section 10. Monitor ROM (MON) Section 11. Timer Interface Module (TIM) Section 12. I/O Ports Section 13. Computer Operating Properly (COP) Section 14. External Interrupt (IRQ) Section 15. Keyboard Interrupt Module (KBI) Section 16. Break Module (BREAK) Section 17. Preliminary Electrical Specifications Section 18. Mechanical Specifications Page List of Figures Page Page Page List of Tables Page Section 1. General Description 1.1 Contents 1.2 Introduction 1.3 Features Page 1.4 MCU Block Diagram Figure 1-1. MCU Block Diagram 68HC(7)08KH12 28 1.5 Pin Assignments Figure 1-2. 64-Pin QFP Assignments (Top View) 1.5.1 Quad Flat Pack (QFP) Package Figure 1-2 Shows the 64-pin QFP assignments. Page Page Page Page Section 2. Memory Map 34 Figure 2-1. Memory Map 2.3 I/O Section 36 Figure 2-2. Control, Status, and Data Registers Page Page Page Page Page Page Table 2-1 is a list of vector locations. 2.4 Monitor ROM Table 2-1. Vector Addresses Page Section 3. Random-Access Memory (RAM) NOTE: 3.1 Contents 3.2 Introduction 3.3 Functional Description NOTE: Section 4. Read-Only Memory (ROM) Page Section 5. Configuration Register (CONFIG) 5.1 Contents 5.2 Introduction 5.3 Functional Description NOTE: Section 6. Central Processor Unit (CPU) 6.3 Features 6.4 CPU Registers Page Page Page Page Page NOTE: 6.5 Arithmetic/Logic Unit (ALU) Page Section 7. System Integration Module (SIM) 7.1 Contents 7.2 Introduction Figure 7-1. SIM Block Diagram 64 Figure 7-2. SIM I/O Register Summary 7.3 SIM Bus Clock Control and Generation 7.4 Reset and System Initialization Page Page Page Page 7.5 SIM Counter 7.6 Exception Control Figure 7-8. Interrupt Processing Page NOTE: Page Page 7.7 Low-Power Modes Page Page NOTE: 7.8 SIM Registers Page Page Page Section 8. Clock Generator Module (CGM) 8.1 Contents 8.2 Introduction 8.3 Features 8.4 Functional Description 90 PN Figure 8-1. CGM Block Diagram R Page Page Page Page a. b. c. Page Page 8.5 I/O Signals NOTE: Page 8.6 CGM Registers Table 8-2. CGM I/O Register Summary Page Page Page Page NOTE: 8.7 Interrupts NOTE: 8.8 Special Modes 8.9 Acquisition/Lock Time Specifications Page Page Page NOTE: Section 9. Universal Serial Bus Module (USB) 9.1 Contents 9.2 Features 9.3 Overview 12MHz 116 Figure 9-1. USB Block Diagram 9.4 I/O Register Description of the HUB function Table 9-1. HUB Control Register Summary Page Table 9-2. HUB Data Register Summary Page Page Page Page Page Page Page NOTE: Page Page Page Page Page Page 9.5 I/O Register Description of the Embedded Device Function Table 9-3. Embedded Device Control Register Summary 136 Table 9-4. Embedded Device Data Register Summary Page Page Page Page Page Page Page Page Page Page Page Page Section 10. Monitor ROM (MON) 10.3 Features 10.4 Functional Description Figure 10-1. Monitor Mode Circuit NOTE: Page Page Page 156 Table 10-3. READ (Read Memory) Command Table 10-4. WRITE (Write Memory) Command Table 10-5. IREAD (Indexed Read) Command Table 10-6. IWRITE (Indexed Write) Command Page Page Page Section 11. Timer Interface Module (TIM) 11.1 Contents 11.2 Introduction 11.3 Features 11.4 Functional Description Figure 11-1. TIM Block Diagram 164 Table 11-1. TIM I/O Register Summary Page Page Page Page Page NOTE: 11.5 Interrupts 11.6 Wait Mode 11.7 TIM During Break Interrupts 11.8 I/O Signals 11.9 I/O Registers Page Page Page Page Page Page NOTE: Page 182 Figure 11-8. TIM Channel Registers (TCH0H/L:TCH1H/L) Section 12. I/O Ports 12.1 Contents 184 12.2 Introduction NOTE: Page 12.3 Port A NOTE: 12.4 Port B NOTE: 12.5 Port C NOTE: 12.6 Port D Page NOTE: 12.7 Port E Page NOTE: Page Page 200 Figure 12-17. Optical Interface Voltage References Figure 12-18. Port E Optical Coupling Interface 12.8 Port F NOTE: 12.9 Port Options Page Page Section 13. Computer Operating Properly (COP) 13.1 Contents 13.2 Introduction 208 13.3 Functional Description Figure 13-1. COP Block Diagram Figure 13-1 shows the structure of the COP module. NOTE: 13.4 I/O Signals Page 13.5 COP Control Register (COPCTL) 13.6 Interrupts 13.7 Monitor Mode 13.8 Low-Power Modes 13.9 COP Module During Break Mode Section 14. External Interrupt (IRQ) 14.4 Functional Description NOTE: Freescale Semiconductor 215 Figure 14-1. IRQ Module Block Diagram Table 14-1. IRQ I/O Port Register Summary Addr. Register Name Bit 7 6 5 4 3 2 1 Bit 0 $001E IRQ Status/Control Register (ISCR) Read: 0000IRQF10 IMASK1 MODE1 Write: ACK1 Reset:00000000 = Unimplemented Page 14.5 IRQ Module During Break Interrupts 14.6 IRQ Status and Control Register (ISCR) Page Section 15. Keyboard Interrupt Module (KBI) 15.1 Contents 15.2 Introduction 15.3 Features Table 15-1. KBI I/O Register Summary 222 15.4 Port-D Keyboard Interrupt Block Diagram Figure 15-1. Port-D Keyboard Interrupt Block Diagram Page NOTE: Page Page Page 228 15.5 Port-E Keyboard Interrupt Block Diagram Figure 15-4. Port-E Keyboard Interrupt Block Diagram Page NOTE: Page Page Page 234 15.6 Port-F Keyboard Interrupt Block Diagram Figure 15-7. Port-F Keyboard Interrupt Block Diagram Page NOTE: Page Page 15.7 Wait Mode 15.8 Stop Mode 15.9 Keyboard Module During Break Interrupts Page Section 16. Break Module (BREAK) 16.1 Contents 16.2 Introduction 16.3 Features 16.4 Functional Description Figure 16-1. Break Module Block Diagram Table 16-1. Break I/O Register Summary 16.5 Break Module Registers Page 16.6 Low-Power Modes Section 17. Preliminary Electrical Specifications 17.1 Contents 17.2 Introduction 17.3 Absolute Maximum Ratings NOTE: 17.4 Functional Operating Range 17.5 Thermal Characteristics 17.6 DC Electrical Characteristics 17.7 Control Timing 17.8 Oscillator Characteristics 17.9 USB DC Electrical Characteristics 17.10 USB Low Speed Source Electrical Characteristics 17.11 USB High Speed Source Electrical Characteristics 17.12 HUB Repeater Electrical Characteristics Low Speed HUB Electrical Characteristics (Root port and downstream ports configured as low speed) Full Speed HUB Electrical Characteristics (Root port and downstream ports configured as full speed) 17.13 USB Signaling Levels 17.14 TImer Interface Module Characteristics 17.15 Clock Generation Module Characteristics 17.15.2 CGM Electrical Specifications 17.15.1 CGM Component Specifications 258 17.15.3 Acquisition/Lock Time Specifications Section 18. Mechanical Specifications 260 18.3 Plastic Quad Flat Pack (QFP) Figure 18-1. 64-Pin Quad-Flat-Pack (Case 840C-04) Page How to Reach Us: