Compaq 21264, EV67 See Appendix B for a listing of the Boundary-Scan Register, References

Models: 21264 EV67

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Notes on IEEE 1149.1 Operation and Compliance

The instruction cache lines are loaded in the reverse order. If the fetch_count(9,0) is zero, then, no instruction cache lines are loaded. Since the valid bits are already cleared by the BiST operation, the first instruction fetch is missed in the instruction cache and the chip seeks instructions from the offchip memory.

Table 11–3 Icache Bit Fields in an SROM Line

Fetch Bit

Icache Data

Fetch Bit

Icache Data

Fetch Bit

Icache Data

0

par-MBZ

86

par-MBZ

172

lp_train

1

c[3]

87

c[0]

173:175

lp_src(2:0)

2:27

i[3](25,20,24,19,23,18,22,17

88:113

i[0](25,20,24,19,3,18,22,17,

176:181

lp_idx(14:9)

 

,21,16:0)

 

21,16:0)

 

 

28

c[2]

114

c[1]

182:186

lp_idx(8:4)

29:42

i[2](25,20,24,19,

115:128

i[1] (25,20,24,19,

187

lp_idx(15)

 

23,18,22,17,21,16:12)

 

23,18,22,17,21,16:12)

 

 

43

parity

129

parity

188:192

lp_ssp[4:0]

44:55

i[2](11:0)

130:141

i[1](11:0)

56

dv[3]

142

dv[0]

57:59

iq[3](2:0)

143:145

iq[0](2:0)

60:65

i[3](26:31)

146:151

i[0](26:31)

66,68

ea[3](2:0)

152:154

ea[0](2:0)

69

dv[2]

155

dv[1]

70,72

iq[2](2:0)

156:158

iq[1](2:0)

73:78

i[2](26:31)

159:164

i[1](26:31)

79:81

ea[2](2:0)

165:167

ea[1](2:0)

82:85

tr(7:4)

168:171

tr(0:3)

 

 

 

 

 

 

Refer to the Alpha Motherboards Software Developer’s Kit (SDK) for example C code that calculates the predecode values of a serial Icache load.

11.6Notes on IEEE 1149.1 Operation and Compliance

1.IEEE 1149.1 port pins on the 21264/EV67 are not pulled up or pulled down on the chip. The necessary pull-up or pull-down function must be implemented on the board.

2.Tms_H should not change when Trst_L is being deasserted.

References

IEEE Std. 1149.1-1993A Test Access Port and Boundary Scan Architecture.

See Appendix B for a listing of the Boundary-Scan Register.

Alpha 21264/EV67 Hardware Reference Manual

Testability and Diagnostics 11–7

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Compaq 21264 See Appendix B for a listing of the Boundary-Scan Register, Icache Bit Fields in an Srom Line, References