Table 3-6, Address/transfer attribute summary – IBM POWERPC 750GL User Manual

Page 146

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User’s Manual
IBM PowerPC 750GX and 750GL RISC Microprocessor

Instruction-Cache and Data-Cache Operation

Page 146 of 377

gx_03.fm.(1.2)

March 27, 2006

Table 3-6. Address/Transfer Attribute Summary

Bus Transaction

A[0–31]

TT[0–4]

TBST

TSIZ[0–2]

GBL

WT

CI

Instruction fetch operations:

Burst (caching-enabled)

PA[0–28] || 0b000

0 1 1 1 0

0

0 1 0

¬ M

1

1*

Single-beat read (caching-inhibited or
cache disabled)

PA[0–28] || 0b000

0 1 0 1 0

1

0 0 0

¬ M

1

¬ I

Single-beat read (caching-inhibited or
cache disabled, 32-bit bus)

PA(0:29) || 00

0 1 0 1 0

1

1 0 0

¬ M

1

¬ I

Data-cache operations:

Cache-block fill (due to load or store
miss)

PA[0–28] || 0b000

A 1 1 1 0

0

0 1 0

¬ M

0

1*

Castout
(normal replacement)

CA[0–26] || 0b00000

0 0 1 1 0

0

0 1 0

1

1

1*

Push (cache-block push due to dcbf or
dcbst)

PA[0–26] || 0b00000

0 0 1 1 0

0

0 1 0

1

0

1*

Snoop copyback

CA[0–26] || 0b00000

0 0 1 1 0

0

0 1 0

1

0

1*

Data-cache bypass operations:

Single-beat read (caching-inhibited or
cache disabled)

PA[0–31]

A 1 0 1 0

1

S S S

¬ M

0

¬ I

Single-beat write (caching-inhibited,
write-through, or cache disabled)

PA[0–31]

0 0 0 1 0

1

S S S

¬ M

¬W

¬ I

Special instructions:

dcbz (address-only)

PA[0–28] || 0b000

0 1 1 0 0

0

0 1 0

0*

0

1*

dcbi (if HID0[ABE] = 1, address-only)

PA[0–26] || 0b00000

0 1 1 0 0

0

0 1 0

¬ M

0

1*

dcbf (if HID0[ABE] = 1, address-only)

PA[0–26] || 0b00000

0 0 1 0 0

0

0 1 0

¬ M

0

1*

dcbst (if HID0[ABE] = 1, address-only)

PA[0–26] || 0b00000

0 0 0 0 0

0

0 1 0

¬ M

0

1*

sync (if HID0[ABE] = 1, address-only)

0x0000_0000

0 1 0 0 0

0

0 1 0

0

0

0

eieio (if HID0[ABE] = 1, address-only)

0x0000_0000

1 0 0 0 0

0

0 1 0

0

0

0

stwcx. (always single-beat write)

PA[0–29] || 0b00

1 0 0 1 0

1

1 0 0

¬ M

¬ W

¬ I

eciwx

PA[0–29] || 0b00

1 1 1 0 0

EAR[28–31]

1

0

0

ecowx

PA[0–29] || 0b00

1 0 1 0 0

EAR[28–31]

1

1

0

Note:

PA = Physical address, CA = Cache address.

W,I,M = WIM state from address translation; ¬ = complement; 0*or 1* = WIM state implied by transaction type in table

For instruction fetches, reflection of the M bit must be enabled through HID0[IFEM].
A = Atomic; high if lwarx, low otherwise

S = Transfer size

Special instructions listed might not generate bus transactions depending on cache state.

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