AMD-K6 AMD [Advanced Micro Devices], AMD-K6 Datasheet - Page 153

• Manufacturer Part Number: AMD-K6
• Description: AMD-K6 Processor
• Manufacturer: AMD [Advanced Micro Devices]

20695H/0—March 1998
Misaligned I/O Read
and Write
Figure 50. Misaligned I/O Transfer
Chapter 6
BE[7:0]#
D[63:0]
A[31:3]
LOCK#
BRDY#
M/IO#
SCYC
ADS#
W/R#
D/C#
CLK
ADDR DATA DATA IDLE ADDR DATA DATA IDLE ADDR DATA
Misaligned I/O Read
Table 22 shows the misaligned I/O read and write cycle order
executed by the AMD-K6. In Figure 50, the least-significant
bytes (LSBs) are transferred first. Immediately after the
processor samples BRDY# asserted, it drives the second bus
cycle to transfer the most-significant bytes (MSBs) to complete
the misaligned bus cycle.
Table 22. Bus-Cycle Order During Misaligned I/O Transfers
LSB
Type of Access
I/O Write
I/O Read
MSB
Bus Cycles
First Cycle
LSBs
LSBs
DATA
DATA
LSB
IDLE ADDR DATA
Misaligned I/O Write
AMD-K6
Second Cycle
®
MSBs
MSBs
Processor Data Sheet
DATA
DATA
MSB
IDLE
135