Computer Hardware User Manual
Table Of Contents
- Contents
- List of Figures
- List of Tables
- About This Manual
- Programming Issues
- Introduction
- Programming Interfaces
- Functional Description
- Memory Maps
- Interrupt Handling
- Cache Coherency (MVME167P)
- Cache Coherency (MVME177P)
- Using Bus Timers
- Indivisible Cycles
- Supervisor Stack Pointer (MC68060)
- Sources of Local Bus Errors
- Error Conditions
- MPU Parity Error
- MPU Offboard Error
- MPU TEA - Cause Unidentified
- MPU Local Bus Time-out
- DMAC VMEbus Error
- DMAC Parity Error
- DMAC Offboard Error
- DMAC LTO Error
- DMAC TEA - Cause Unidentified
- SCC Retry Error
- SCC Parity Error
- SCC Offboard Error
- SCC LTO Error
- LAN Parity Error
- LAN Offboard Error
- LAN LTO Error
- SCSI Parity Error
- SCSI Offboard Error
- SCSI LTO Error
- VMEchip2
- Introduction
- Functional Blocks
- LCSR Programming Model
- Programming the VMEbus Slave Map Decoders
- VMEbus Slave Ending Address Register 1
- VMEbus Slave Starting Address Register 1
- VMEbus Slave Ending Address Register 2
- VMEbus Slave Starting Address Register 2
- VMEbus Slave Address Translation Address Offset Register 1
- VMEbus Slave Address Translation Select Register 1
- VMEbus Slave Address Translation Address Offset Register 2
- VMEbus Slave Address Translation Select Register 2
- VMEbus Slave Write Post and Snoop Control Register 2
- VMEbus Slave Address Modifier Select Register 2
- VMEbus Slave Write Post and Snoop Control Register 1
- VMEbus Slave Address Modifier Select Register 1
- Programming the Local-Bus-to-VMEbus Map Decoders
- Local Bus Slave (VMEbus Master) Ending Address Register 1
- Local Bus Slave (VMEbus Master) Starting Address Register 1
- Local Bus Slave (VMEbus Master) Ending Address Register 2
- Local Bus Slave (VMEbus Master) Starting Address Register 2
- Local Bus Slave (VMEbus Master) Ending Address Register 3
- Local Bus Slave (VMEbus Master) Starting Address Register 3
- Local Bus Slave (VMEbus Master) Ending Address Register 4
- Local Bus Slave (VMEbus Master) Starting Address Register 4
- Local Bus Slave (VMEbus Master) Address Translation Address Register 4
- Local Bus Slave (VMEbus Master) Address Translation Select Register 4
- Local Bus Slave (VMEbus Master) Attribute Register 4
- Local Bus Slave (VMEbus Master) Attribute Register 3
- Local Bus Slave (VMEbus Master) Attribute Register 2
- Local Bus Slave (VMEbus Master) Attribute Register 1
- VMEbus Slave GCSR Group Address Register
- VMEbus Slave GCSR Board Address Register
- Local-Bus-to-VMEbus Enable Control Register
- Local-Bus-to-VMEbus I/O Control Register
- ROM Control Register
- Programming the VMEchip2 DMA Controller
- DMAC Registers
- EPROM Decoder, SRAM and DMA Control Register
- Local-Bus-to-VMEbus Requester Control Register
- DMAC Control Register 1 (bits 07)
- DMAC Control Register 2 (bits 815)
- DMAC Control Register 2 (bits 07)
- DMAC Local Bus Address Counter
- DMAC VMEbus Address Counter
- DMAC Byte Counter
- Table Address Counter
- VMEbus Interrupter Control Register
- VMEbus Interrupter Vector Register
- MPU Status and DMA Interrupt Count Register
- DMAC Status Register
- Programming the Tick and Watchdog Timers
- VMEbus Arbiter Time-Out Control Register
- DMAC Ton/Toff Timers and VMEbus Global Time-out Control Register
- VME Access, Local Bus, and Watchdog Time-out Control Register
- Prescaler Control Register
- Tick Timer 1 Compare Register
- Tick Timer 1 Counter
- Tick Timer 2 Compare Register
- Tick Timer 2 Counter
- Board Control Register
- Watchdog Timer Control Register
- Tick Timer 2 Control Register
- Tick Timer 1 Control Register
- Prescaler Counter
- Programming the Local Bus Interrupter
- Local Bus Interrupter Status Register (bits 2431)
- Local Bus Interrupter Status Register (bits 1623)
- Local Bus Interrupter Status Register (bits 815)
- Local Bus Interrupter Status Register (bits 07)
- Local Bus Interrupter Enable Register (bits 2431)
- Local Bus Interrupter Enable Register (bits 1623)
- Local Bus Interrupter Enable Register (bits 815)
- Local Bus Interrupter Enable Register (bits 07)
- Software Interrupt Set Register (bits 815)
- Interrupt Clear Register (bits 2431)
- Interrupt Clear Register (bits 1623)
- Interrupt Clear Register (bits 815)
- Interrupt Level Register 1 (bits 2431)
- Interrupt Level Register 1 (bits 1623)
- Interrupt Level Register 1 (bits 815)
- Interrupt Level Register 1 (bits 07)
- Interrupt Level Register 2 (bits 2431)
- Interrupt Level Register 2 (bits 1623)
- Interrupt Level Register 2 (bits 815)
- Interrupt Level Register 2 (bits 07)
- Interrupt Level Register 3 (bits 2431)
- Interrupt Level Register 3 (bits 1623)
- Interrupt Level Register 3 (bits 815)
- Interrupt Level Register 3 (bits 07)
- Interrupt Level Register 4 (bits 2431)
- Interrupt Level Register 4 (bits 1623)
- Interrupt Level Register 4 (bits 815)
- Interrupt Level Register 4 (bits 07)
- Vector Base Register
- I/O Control Register 1
- I/O Control Register 2
- I/O Control Register 3
- Miscellaneous Control Register
- Programming the VMEbus Slave Map Decoders
- GCSR Programming Model
- PCCchip2
- Introduction
- Functional Description
- Overall Memory Map
- Programming Model
- Chip ID Register
- Chip Revision Register
- General Control Register
- Vector Base Register
- Programming the Tick Timers
- Tick Timer 1 Compare Register
- Tick Timer 1 Counter
- Tick Timer 2 Compare Register
- Tick Timer 2 Counter
- Prescaler Count Register
- Prescaler Clock Adjust Register
- Tick Timer 2 Control Register
- Tick Timer 1 Control Register
- General Purpose Input Interrupt Control Register
- General Purpose Input/Output Pin Control Register
- Tick Timer 2 Interrupt Control Register
- Tick Timer 1 Interrupt Control Register
- SCC Error Status and Interrupt Control Registers
- LANC Error Status and Interrupt Control Registers
- Programming the SCSI Error Status and Interrupt Registers
- Programming the Printer Port
- Printer ACK Interrupt Control Register
- Printer FAULT Interrupt Control Register
- Printer SEL Interrupt Control Register
- Printer PE Interrupt Control Register
- Printer BUSY Interrupt Control Register
- Printer Input Status Register
- Printer Port Control Register
- Chip Speed Register
- Printer Data Register
- Interrupt Priority Level Register
- Interrupt Mask Level Register
- MCECC Functions
- Introduction
- Features
- Functional Description
- General Description
- Performance
- Cache Coherency
- ECC
- Cycle Types
- Error Reporting
- Single Bit Error (Cycle Type = Burst Read or Non-Burst Read)
- Double Bit Error (Cycle Type = Burst Read or Non-Burst Read)
- Triple (or Greater) Bit Error (Cycle Type = Burst Read or Non-Burst Read)
- Cycle Type = Burst Write
- Single Bit Error (Cycle Type = Non-Burst Write)
- Double Bit Error (Cycle Type = Non-Burst Write)
- Triple (or Greater) Bit Error (Cycle Type = Non-Burst Write)
- Single Bit Error (Cycle Type = Scrub)
- Double Bit Error (Cycle Type = Scrub)
- Triple (or Greater) Bit Error (Cycle Type = Scrub)
- Error Logging
- Scrub
- Refresh
- Arbitration
- Chip Defaults
- Programming Model
- Chip ID Register
- Chip Revision Register
- Memory Configuration Register
- Base Address Register
- DRAM Control Register
- BCLK Frequency Register
- Data Control Register
- Scrub Control Register
- Scrub Period Register Bits 15-8
- Scrub Period Register Bits 7-0
- Chip Prescaler Counter
- Scrub Time On/Time Off Register
- Scrub Prescaler Counter (Bits 21-16)
- Scrub Prescaler Counter (Bits 15-8)
- Scrub Prescaler Counter (Bits 7-0)
- Scrub Timer Counter (Bits 15-8)
- Scrub Timer Counter (Bits 7-0)
- Scrub Address Counter (Bits 26-24)
- Scrub Address Counter (Bits 23-16)
- Scrub Address Counter (Bits 15-8)
- Scrub Address Counter (Bits 7-4)
- Error Logger Register
- Error Address (Bits 31-24)
- Error Address (Bits 23-16)
- Error Address (Bits 15-8)
- Error Address (Bits 7-4)
- Error Syndrome Register
- Defaults Register 1
- Defaults Register 2
- SDRAM Configuration Register
- Initialization
- Syndrome Decoding
- Summary of Changes
- Printer and Serial Port Connections
- Related Documentation
- Index

Using Bus Timers
http://www.motorola.com/computer/literature 1-51
1
Using Bus Timers
This section illustrates the use of bus timers by describing the sequence of
events when the MPU on one single-board computer accesses the Local
Bus memory on another single-board computer using the VMEbus. This
scenario involves three bus timers, which normally should be set to quite
different values:
The sequence begins when the MPU asserts a request for the Local Bus.
The MPU must wait until the Local Bus is released by the current bus
master before its cycle can begin. When the MPU is granted the Local Bus,
it begins its cycle and the Local Bus timer starts counting. It continues to
count until an address decode of the VMEbus address space is detected and
then the timer stops. This is normally a very short period of time. In fact,
all Local Bus non-error bus accesses are normally very short, such as the
time to access onboard memory. Therefore, it is recommended this timer
be set to a small value, such as 8 µsec.
The next timer to take over when one single-board computer accesses
another is the VMEbus access timer. This measures the time from when
the VMEbus has been address-decoded (and hence a VMEbus request has
been made) to when VMEbus mastership has been granted. Because
experience has shown that some VME systems can become very busy, we
recommend this time-out be set to a large value, such as 32 msec. For
debug purposes this value can also be set to infinity.
Once the VMEbus has been granted, a third timer takes over. This is the
global VMEbus timer. This timer starts when a transfer actually begins
(DS0 or DS1 goes active) and ends when that transfer completes (DS0 or
Local bus timer Measures the time an access to an onboard resource
takes
VMEbus access
timer
Measures the time from when the VMEbus request has
been initiated to when a VMEbus grant has been
obtained
Global VMEbus
timer
Measures the time from when a VMEbus cycle begins to
when it completes