Compaq 21264 Network Card User Manual


 
21264/EV68A Hardware Reference Manual
Internal Processor Registers 5–23
Ibox IPRs
5.2.22 Performance Counter Control Register – PCTR_CTL
The performance counter control register (PCTR_CTL) is a read-write register that
controls the function of the performance counters for either aggregate counting or Pro-
fileMe sampling counting.
Usage of PCTR_CTL in performance monitoring is described in Section 6.10.
Figure 5–25 shows the performance counter control register.
Figure 5–25 Performance Counter Control Register
Table 5–15 describes the performance counter control register fields.
FPE [2] RW,1 Floating-point enable—if clear, floating-point instructions
generate FEN exceptions. This bit is set by hardware on
reset.
PPCE [1] RW Process performance counting enable.
Enables performance counting for an individual process
with counters PCTR0 or PCTR1, which are enabled by set-
ting PCT0_EN or PCT1_EN, respectively.
Performance counting for the entire system can be enabled
by setting I_CTL[SPCE]. See Section 5.2.15 for more infor-
mation.
See Section 6.10 for information about performance count-
ing.
Reserved [0]
Table 5–15 Performance Counter Control Register Fields Description
Name Extent Type Description
SEXT(PCTR0_CTL[47]) [63:48] RO When read, this field is sign extended from PCTR_CTL[47]. Writes
to this field are ignored.
Table 5–14 Process Context Register Fields Description (Continued)
Name Extent Type Description
63 48 2847 2726 625 543210
SEXT(PCTR0_CTL[47])
PCTR0[19:0]
PM_STALLED
PM_KILLED_BM
PCTR1[19:0]
SL0
SL1[1:0]
VAL
TAK
LK
99
-
003
4A