User’s Manual
IBM PowerPC 750GX and 750GL RISC Microprocessor
gx_08.fm.(1.2)
March 27, 2006
Bus Interface Operation
Page 315 of 377
Figure 8-22 shows the use of the TEA signal. Note that all bidirectional signals are tristated between bus
tenures. Also note:
• The first data beat of the read burst (in clock 0) is the critical quadword.
• The TEA
signal truncates the burst write transfer on the third data beat.
• The 750GX eventually causes an exception to be taken on the TEA
event.
Figure 8-22. Use of Transfer Error Acknowledge (TEA
)
BR
BG
ABB
TS
A[0–31]
TT[0–4]
TBST
GBL
AACK
ARTRY
DBG
DBB
D[0–63]
TA
DRTRY
TEA
CPU A
In 0
1 2 3 4 5 6 7 8 9 1011121314151617
CPU A CPU A
Read Write Read
In 1 In 2 In 3 Out 0 Out 1 Out 2 In 0 In 1 In 3In 2
1 2 3 4 5 6 7 8 9 1011121314151617