User's Manual

Turbo PMAC User Manual
24 Turbo PMAC System Configuration and Auto Configuration
I4903 is also a collection of 16 independent bits, each reporting the type of MACRO IC at one of the 16
possible locations. A bit value of 1 indicates a DSPGATE2 IC; a bit value of 0 indicates a
MACROGATE IC (or no IC present if the corresponding bit of I4900 is 0).
While it is possible for up to 16 MACRO ICs to be installed in a Turbo PMAC system, only four of these
can be supported at any time by automatic firmware functions. I20 – I23 contain the base addresses of
these four ICs. When the system is re-initialized, these variables are set to values for the four ICs found
with the lowest base addresses.
DPRAM IC Configuration
On power-up/reset, the Turbo PMAC CPU automatically tests for the presence of all possible dual-ported
RAM ICs and reports the results in I4904. I4904 is a collection of eight independent bits, each reporting
the presence of a DPRAM IC at one of the eight possible locations. Only one of these ICs can be
supported at any time by automatic firmware functions. I24 contains the base address of this IC.
CPU Section Configuration
On power-up/reset, the Turbo PMAC automatically tests for the configuration of its own CPU section and
reports the results in I4908. I4908 is a 36-bit value reporting the CPU type, active memory size, DPRAM
size, battery-backed RAM size, flash memory size, presence of auxiliary serial port, part number, and
vendor ID.
UBUS Accessory Board Identification
The Turbo PMAC can report detailed information about accessory boards installed on the UBUS
expansion port in UMAC Turbo systems. This information is reported in variable I4910 – I4965. Each is
a 36-bit variable with the following contents:
Vendor ID: 8 bits
Options present: 10 bits
Revision number: 4 bits
Card ID (part number): 14 bits
Each variable can report one part or all parts of this information, depending on the setting of I39. If I39 is
set to 5, the variable reports the base address of the accessory board instead.
I4910 – I4925 report this information for the 16 possible accessory boards with Servo ICs, such as the
Acc-24E2, 24E2A, 24E2S, and 51E.
I4926 – I4941 report this information for the 16 possible accessory boards with MACRO ICs, such as the
Acc-5E.
I4942 – I4949 report this information for the 8 possible accessory boards with DPRAM ICs, such as the
Acc-54E USB/Ethernet interface.
I4950 – I4965 report this information for the 16 possible accessory boards with I/O ICs, such as the Acc-
14E, 28E, 36E, 53E, and 59E. (The Acc-9E, 10E, 11E, and 12E I/O boards currently cannot provide this
information.)
Setting System Clock Frequencies
The phase clock and servo clock signals set the heartbeat for the entire Turbo PMAC system,
synchronizing both hardware and software operations. While the factory default frequencies – 9.04 kHz
for the phase clock and 2.26 kHz for the servo clock – are suitable for most applications, some
applications will either require changes, or could benefit from changes in one or both of these frequencies.
The hardware tasks that are driven by the phase and servo clock signals include:
• Latching of encoder counters
• Latching of parallel feedback registers
• Strobing of A/D converters and latching of resulting data
• Output to D/A converters