Digital Core Design

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D6803

8-bit Microcontroller

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The D6803 is synthesisable, SOFT Microcontroller IP Core, fully compatible with the Motorola MC6803. It can be used as direct replacement for the MC6803 Microcontrollers.
 In the standard configuration, the core has integrated on-chip, major peripheral functions. An asynchronous serial communications interface (SCI) is included, as well as the main 16-bit, three-function programmable timer. Software-controlled power-saving mode - WAIT, is available to conserve additional power. This mode makes the D6803 IP Core especially attractive for automotive and battery-driven applications.
The D6803 has a built-in real time hardware on chip debugger - the DoCDTM, allowing easy software debugging and validation.
The D6803 is fully customizable - it is delivered in the exact configuration, to meet user's requirements. There is no need to pay extra, for not used features and wasted silicon. It includes fully automated testbench with complete set of tests, allowing easy package validation, at each stage of SoC design flow.

Each of the DCD's D6803 Core, has built-in support for DCD Hardware Debug System, called DoCDTM. It is a real-time hardware debugger which provides debugging capability of a whole System on Chip (SoC).
Unlike other on-chip debuggers, the DoCDTM provides a non-intrusive debugging of running application. It can halt, run, step into or skip an instruction, read/write any contents of microcontroller, including all registers, SFRs, including user defined peripherals and data and program memories. More details about DCD on Chip Debugger


Family summary

Family IP Core Architecture
type		 Memory space DoCDTM UART (SCI) SPI M/S IO Ports Watchdog
Timer		 Timer Compare / Capture Pulse
accumulator		 READY
pin		 Chip Selects Gatecount
HC05, HC08 DF6805 fast 64k + + - 4 + 1 2/2 - + - 7000
- DF6808 fast 64k + + - 4 + 1 2/2 - + - 8300
- D68HC05 legacy 64k + + + 4 + 1 1/1 - - - -
- D68HC08 legacy 64K + + + 4 + 1 2/1 - - - 10000
HC11 DF6811E fast 64k + + + 5 + 1 5/4 + + - 12000
- DF6811F fast 64k + + + 7 + 1 5/4 + + - 14000
- DF6811K fast 1M + + + 10 + 3 13/6 + + - 21000
- D68HC11E legacy 64k + + + 5 + 1 5/4 + - - 13000
- D68HC11K legacy 1M + + 1 10 + 3 13/6 + - 4 21000
- D68HC11F legacy 64k + + + 7 + 1 5/4 - - 4 13500
6802, 6803 DF6802 fast 64k + - - - - - - - - - -
- DF6803 fast 64k + + + 4 - 1 + - - - -
- D6802 legacy 64k + - - - - - - - - - 3600
- D6803 legacy 64k + + + 4 - 1 + - - - 6000

The main features of each D68XX and DF68XX family member, have been summarized in the table above. It gives a brief member characteristic, helping you to select the most suitable IP Core for your application. You can specify your own peripheral set (including listed above and the others) and request the core modifications.

CPU Features

Symbol

 clk
 por
 port1
 port2
 port3
 port4
 irq
 nmi
 docddatai
 clkdocd
docddatao 
docdclk 

Pins description
PinTypeDescription
clkinputGlobal clock
porinputGlobal reset Power On Reset
port1inputBidirectional Port 1
port2inputBidirectional Port 2, shared with SCI and programmable timer devices
port3inputBidirectional Port 3, shared with Low address Byte and Data bus. (Demultiplexed Address/Data bus is also possible)
port4inputBidirectional Port 4, shared with high address byte in Expanded mode
irqinputInterrupt input
nmiinputNon-maskable interrupt input
docddataiinputDoCDTM serial data input
clkdocdinputClock signal to DoCDTM On chip Debugger module. This separate clock line allow DoCDTM to operate during the SLEEP mode (major clock CLK is stopped).
docddataooutputDoCDTM serial data output
docdclkoutputDoCDTM serial data clock line

Block Diagram
SCIThe SCI is a full-duplex UART type asynchronous system, using standard non return to zero (NRZ) format : 1 start bit and stop bit. The Core resynchronizes the receiver bit clock on all one to zero transitions in the bit stream. Therefore differences in baud rate between the sending device and the SCI are not as likely to cause reception errors. Three logic samples are taken near the middle of data bit time, and majority logic decides the sense for the bit. For the start and stop bits seven logic samples are taken. Even if noise causes one of these samples to be incorrect, the bit will still be received correctly. The receiver also has the ability to enter a temporary standby mode (called receiver wakeup) to ignore messages intended for a different receiver. Logic automatically wakes up the receiver in time to see the first character of the next message. This wakeup feature greatly reduces CPU overhead in multidrop SCI networks. The SCI transmitter can produce queued characters of idle (whole characters of all logic 1) and break (whole characters of all logic 0). In addition to the usual transmit data register empty (TDRE) status flag.
I/O PortsGeneral Purpose I/O Ports. When enabled, the I/O Ports are shared with particular on chip peripherals: SCI and TIMER.
port1
port2
port3
port4
Timer with Compare CaptureThe programmable timer is based on free-running 16-bit counter and input capture/output compare circuitry. The timer can be used for many purposes, including measuring pulse length of two input signals and generating two output signals. The timer has a 16-bit architecture, hence each specific functional segment is represented by two 8-bit registers. These registers contain the high and the low byte of that functional block. Accessing the low byte of a specific timer function, allows full control of that function, however, an access of the high byte, inhibits that specific timer function, until the byte is also accessed.
Control UnitControl unit performs the core synchronization and data flow control.
Opcode DecoderPerforms an opcode decoding instruction and control functions for all other blocks.
ALUArithmetic Logic Unit performs the arithmetic and logic operations, during execution of an instruction. It contains accumulator (A, B), Condition Code Register (CCREG), Index register X and related logic, like arithmetic unit, logic unit, multiplier and divider.
Interrupt ControllerInterrupt Controller – Interrupt Control module is responsible for the interrupt manage system, for the processing of the external and internal interrupts and exceptions. It manages auto-vectored interrupt cycles, priority resolving and correct vector numbers creation.
irq
nmi
DoCDTM DoCDTM Debug Unit is a real-time hardware debugger, which provides debugging capability of a whole SoC system. Unlike other on-chip debuggers, DoCDTM ensures non-intrusive debugging of running application. It can halt, run, step into or skip an instruction, read/write any contents of microcontroller, including all registers, internal and external program memories, all SFRs, including user defined peripherals. Hardware breakpoints can be set and controlled on program memory, internal and external data memories, as well as on SFRs. Hardware breakpoint is executed, if any write/read occurs at particular address, with certain data pattern or without pattern. The DoCDTM system includes three-wire interface and complete set of tools, to communicate and work with core in real time debugging. It is built as scalable unit and some features can be turned off, to save silicon and reduce power consumption. When debugger is not used, it is automatically switched to power save mode. Finally, when debug option is no longer used, whole debugger is turned off.
The separate DoCDTM clock line, allows debugger to operate in the SLEEP mode (major clock line CLK is stopped).
docddatai
docddatao
docdclk
clkdocd
clk
por
Data bus Internal 8-bit data bus.
SFR data bus 8-bit Special Function Registers bus is used to inter-communication of all processors" peripherals. It allows easy management of system architecture.

Units
SCI
The SCI is a full-duplex UART type asynchronous system, using standard non return to zero (NRZ) format : 1 start bit and stop bit. The Core resynchronizes the receiver bit clock on all one to zero transitions in the bit stream. Therefore differences in baud rate between the sending device and the SCI are not as likely to cause reception errors. Three logic samples are taken near the middle of data bit time, and majority logic decides the sense for the bit. For the start and stop bits seven logic samples are taken. Even if noise causes one of these samples to be incorrect, the bit will still be received correctly. The receiver also has the ability to enter a temporary standby mode (called receiver wakeup) to ignore messages intended for a different receiver. Logic automatically wakes up the receiver in time to see the first character of the next message. This wakeup feature greatly reduces CPU overhead in multidrop SCI networks. The SCI transmitter can produce queued characters of idle (whole characters of all logic 1) and break (whole characters of all logic 0). In addition to the usual transmit data register empty (TDRE) status flag.
I/O Ports
General Purpose I/O Ports. When enabled, the I/O Ports are shared with particular on chip peripherals: SCI and TIMER.
Timer with Compare Capture
The programmable timer is based on free-running 16-bit counter and input capture/output compare circuitry. The timer can be used for many purposes, including measuring pulse length of two input signals and generating two output signals. The timer has a 16-bit architecture, hence each specific functional segment is represented by two 8-bit registers. These registers contain the high and the low byte of that functional block. Accessing the low byte of a specific timer function, allows full control of that function, however, an access of the high byte, inhibits that specific timer function, until the byte is also accessed.

Control Unit
Control unit performs the core synchronization and data flow control.
Opcode Decoder
Performs an opcode decoding instruction and control functions for all other blocks.
ALU
Arithmetic Logic Unit performs the arithmetic and logic operations, during execution of an instruction. It contains accumulator (A, B), Condition Code Register (CCREG), Index register X and related logic, like arithmetic unit, logic unit, multiplier and divider.

Interrupt Controller
Interrupt Controller – Interrupt Control module is responsible for the interrupt manage system, for the processing of the external and internal interrupts and exceptions. It manages auto-vectored interrupt cycles, priority resolving and correct vector numbers creation.
DoCDTM
DoCDTM Debug Unit is a real-time hardware debugger, which provides debugging capability of a whole SoC system. Unlike other on-chip debuggers, DoCDTM ensures non-intrusive debugging of running application. It can halt, run, step into or skip an instruction, read/write any contents of microcontroller, including all registers, internal and external program memories, all SFRs, including user defined peripherals. Hardware breakpoints can be set and controlled on program memory, internal and external data memories, as well as on SFRs. Hardware breakpoint is executed, if any write/read occurs at particular address, with certain data pattern or without pattern. The DoCDTM system includes three-wire interface and complete set of tools, to communicate and work with core in real time debugging. It is built as scalable unit and some features can be turned off, to save silicon and reduce power consumption. When debugger is not used, it is automatically switched to power save mode. Finally, when debug option is no longer used, whole debugger is turned off.
The separate DoCDTM clock line, allows debugger to operate in the SLEEP mode (major clock line CLK is stopped).