TC1796
System Units (Vol. 1 of 2)
LMB External Bus Unit
User’s Manual
13-56
V2.0, 2007-07
EBU, V2.0
Figure 13-19 Demultiplexed External Bus Write Access Cycle
above shows an example of a write access to a demultiplexed device. This
type of access cycle consists of two to five phases as follows:
•
Address Phase (compulsory)
•
Command Delay Phase (optional)
•
Command Phase (compulsory)
•
Data Hold Phase (optional)
•
Recovery Phase (optional)
The example shows an access cycle with all five phases programmed for a duration of
one LMBCLK cycle.
1) All phases programmed to one LMBCLK period length.
2) These phases are optional and can be skipped.
3) BCx signals can be asserted either with CSx or RD/WR.
LMBCLK
1)
A[23:0]
Address
ADV
AP
(1 to n)
CD
2)
(0 to n)
CP
(1 to n)
DH
2)
(0 to n)
next AP
Next. A.
CSx
RD
RD/WR
MR/W
Data out
D[31:0]
BCx
3)
3)
RP
2)
(0 to n)
MCT05730
Notes: