Sun Microelectronics
156
UltraSPARC User’s Manual
MID<4:0>
: Module (processor) ID register. Identifies the slot in which the
module resides; hardwired to the slot number from the connector pins.
PCAP<16:0>
: Processor Capabilities. Shadows the following fields in the
UPA_PORT_ID Register.
• PINT_RDQ<16:15>
• PREQ_DQ<14:9>
• PREQ_RQ<8:5>
• UPACAP<4:0>
8.4 Ancillary State Registers
8.4.1 Overview of ASRs
SPARC-V9 provides up to 32 Ancillary State Registers (ASRs 0 .. 31). ASRs 0 .. 6 are
defined by the SPARC-V9 ISA; ASRs 7 .. 15 are reserved for future use by the ar-
chitecture. ASRs 16 .. 31 are available for use by an implementation.
8.4.2 SPARC-V9-Defined ASRs
Table 8-3 defines the SPARC-V9 ASRs that must be supported by a conforming
processor implementation.
1.
An attempt to read this register by non-privileged software with NPT = 1 causes a
privileged_action
trap. The tick
register can only be written with the privileged wrpr instruction.
2.
Read-only—an attempt to write this register causes an
illegal_instruction
trap.
Table 8-3
Mandatory SPARC-V9
ASRs
ASR
Value
ASR Name
Access
Description
Section
00
16
Y_REG
RW
Y register
V9
02
16
COND_CODE_REG
RW
Condition code register
V9
03
16
ASI_REG
RW
ASI register
V9
04
16
TICK_REG
R
1,2
TICK register
V9
05
16
PC
R
2
Program Counter
V9
06
16
FP_STATUS_REG
RW
Floating-point status register
V9
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com