Intel 80200 Computer Hardware User Manual


 
10-24 March, 2003 Developers Manual
Intel
®
80200 Processor based on Intel
®
XScale
Microarchitecture
External Bus
10.3.10 Hold
Figure 10-14 shows an example of hold being asserted to stop new transactions being issued. The
Intel
®
80200 processor floats the issue bus pins and issues no transactions until HldA is deasserted.
The Hold signal assertion does not affect the data bus, which continues to operate normally. Read
data for requests A and B continue to return.
“Rd C” shows the Intel
®
80200 processor requesting another access after Hold has been
deasserted. If Hold had continued to be asserted, another bus master could take control of the
request bus.
Figure 10-14. Hold Assertion
Rd A Rd B Rd C
0x581 0x0 0x0
Rd A Rd B0 Rd B1 Rd B2
0x0
0
0
0
1
0
1
0
1
0
0x9700x35C
Rd B3
0ns 25ns 50ns 75ns 100ns
MCLK
ADS#/LEN[2]
Lock/LEN[1]
W/R#/LEN[0]
A
Hold
HldA
DValid
CWF
D
BE#
DCB
Abort