IBM powerpc 750gx 사용자 설명서
User’s Manual
IBM PowerPC 750GX and 750GL RISC Microprocessor
gx_07.fm.(1.2)
March 27, 2006
March 27, 2006
Signal Descriptions
Page 259 of 377
7.2.4.3 Transfer Burst (TBST)
The transfer burst (TBST) signal is an input/output signal on the 750GX.
Transfer Burst (TBST)—Output
Transfer Burst (TBST)—Input
Timing
Assertion/
Negation/
High
Impedance
Negation/
High
Impedance
The same as A[0–31].
Table 7-3. Data-Transfer Size
TBST
TSIZ[0–2]
Transfer Size
Asserted
010
Burst (32 bytes)
Negated
000
8 bytes
Negated
001
1 byte
Negated
010
2 bytes
Negated
011
3 bytes
Negated
100
4 bytes
Negated
101
5 bytes
Negated
110
6 bytes
Negated
111
7 bytes
1. Not generated by the 750GX.
State
Asserted
Indicates that a burst transfer is in progress.
Negated
Indicates that a burst transfer is not in progress.
For external control instructions (eciwx and ecowx), TBST is used to output
bit 28 of the EAR, which is used to form the resource ID (TBST||TSIZ0–
TSIZ2).
bit 28 of the EAR, which is used to form the resource ID (TBST||TSIZ0–
TSIZ2).
Timing
Assertion/
Negation/
High
Impedance
Negation/
High
Impedance
The same as A[0–31].
State
Asserted/
Negated
Negated
Used when snooping for single-beat reads (read with no intent to cache).
Timing
Assertion/
Negation
Negation
The same as A[0–31].