Reference Manual

Turbo PMAC/PMAC2 Software Reference
Turbo PMAC Global I-Variables 51
On re-initialization – either on resetting with the E3 re-initialization jumper ON or on issuing the
$$$*** command, Turbo PMAC will auto-detect which DPRAM ICs are present, and set I24 to the base
address of the DPRAM IC with the lowest base address. If no DPRAM ICs are found, I24 will be set to 0
instead.
The automatic DPRAM communications functions reference registers in a DPRAM IC, whose addresses
are relative to the address contained in I24. These addresses are established at power-up/reset. If the
value of I24 is incorrect at power-up/reset, these functions will not work. To select a new DPRAM IC
that the CPU will use for the automatic DPRAM IC functions, it is necessary to change I24, issue the
SAVE command, and reset the Turbo PMAC.
If the saved value of I24 is 0 at power-up/reset, the DPRAM addresses will be set up for a DPRAM base
address of $060000.
The following are Turbo PMAC addresses where DPRAM ICs can be found:
Address
Location
Address
Location
$060000
Main board or CPU board
$06F000
UBUS DPRAM board w/ SW=1100
$064000
UMAC-CPCI bridge board*
$074000
UBUS DPRAM board w/ SW=0010
$06C000
UBUS DPRAM board w/ SW=0000
$075000
UBUS DPRAM board w/ SW=0110
$06D000
UBUS DPRAM board w/ SW=0100
$076000
UBUS DPRAM board w/ SW=1010
$06E000
UBUS DPRAM board w/ SW=1000
$077000
UBUS DPRAM board w/ SW=1110
*Not auto-detected on re-initialization.
See Also:
Dual-Ported RAM Communications
I-Variables I47 – I50, I55 – I58, I4904, I4942 – I4949
I26 UMAC Electrical MACRO Enable
Range: 0 – $F (0 – 15)
Units: none
Default: 0
I26 controls whether the MACRO ICs on UMAC ACC-5E boards are configured for optical-fiber
MACRO transceivers or RJ-45 electrical MACRO transceivers. I26 is a 4-bit value, with each bit
corresponding to one of the four MACRO ICs whose addresses are specified by I20 – I23. If the bit is set
to the default value of 0, that MACRO IC is configured for a fiber transceiver. If the bit is 1, that
MACRO IC is configured for an RJ-45 electrical transceiver.
Bit “n” of I26 controls the configuration of the MACRO IC addressed by variable I2n, which is called
MACRO IC “n” (e.g. bit 0 controls the IC of I20, MACRO IC 0). If fewer than 4 MACRO ICs are
present, the settings of bits of I26 corresponding to “missing” MACRO ICs are not important.
I26 is used only on power-up/reset, so to change the effect of I26, the user must change the value, issue a
SAVE command, and reset or cycle power on the UMAC.
Examples:
I26=$0 ; All MACRO ICs use fiber
I26=$F ; All MACRO ICs use RJ-45
I26=$3 ; MACRO ICs 0 & 1 use RJ-45, MACRO ICs 2 & 3 use fiber
I27 Alternate TWS Input Format
Range: 0 – 1
Units: none