Motorola CPCI-6020 ユーザーズマニュアル

ページ / 168
Other Harrier Resources
Functional Description
CPCI-6020 CompactPCI Single Board Computer Installation and Use (6806800A51C)
93
 
4.9
Other Harrier Resources
The following subsections discussion other resources that are available through the Harrier 
ASIC.
4.9.1
I
2
C Bus Resources - Serial EEPROM
The CPCI-6020 contains two 8 KB Serial EEPROM devices onboard and provisions for four 
256-byte Serial EEPROM devices on memory mezzanines. 
z
One 8 KB Serial EEPROM provides for Vital Product Data (VPD) storage of the module 
hardware configuration
z
One 8 KB device for storage of user configuration data. 
The contents of the 8 KB devices are accessed by providing a two-byte address with the same 
device ID, instead of the standard one-byte address as used in the 256-byte devices. The 256-
byte devices provide for Serial Presence Detect (SPD) memory configuration information. The 
Serial EEPROMs for VPD, user data and memory attached to Harrier A are accessed through 
I
2
C port 0 in the Harrier A ASIC. 
The Serial EEPROM’s for memory attached to Harrier B are accessed through I
2
C port 0 in the 
Harrier B ASIC. Refer to the CPCI-6020 CompactPCI Single Board Computer Programmer’s 
Reference Guide
 for SROM device address assignments.
4.9.2
Asynchronous Serial Ports
The CPCI-6020 provides two asynchronous serial interfaces. UART0 and UART1 in the Harrier 
A provide the 16550 compatible UART controllers. The UART0 port signals are wired to an RS-
232 transceiver which interfaces to the front panel RJ-45 connector. The UART0 port may 
optionally be wired to the backplane via J5 instead. The UART1 port is wired to the J5 connector 
only. An onboard 1.8432 MHz oscillator provides the baud rate clock for the UARTs. Refer to 
the Harrier Application Specific Integrated Circuit Programmer’s Reference Guide for additional 
UART information.
4.9.3
32-Bit Timers
Four 32-bit timers are provided by each Harrier (MPIC) that may be used for system timing or 
to generate periodic interrupts. Each timer is driven by a divide-by-eight prescaler which is 
synchronized to the PPC processor clock. For a 100 MHz processor bus, the timer frequency 
would be 12.5 MHz. Refer to the Harrier Engineering Specification for additional information 
and programming details on these timers.
4.9.4
Watchdog Timers
Both Harrier ASICs contains two Watchdog Timers, WDT1 and WDT2. Each timer is 
functionally equivalent but independent. These timers will continuously decrement until they 
reach a count of 0 or are reloaded by software. The time-out period is programmable from 1 
microsecond up to 32 minutes. If the timer count reaches 0, a timer output signal will be