
L64005 MPEG-2 Audio/Video Decoder Technical Manual
2-15
Final Rev F
Copyright 1996 by LSI Logic Corporation. All rights reserved.
2.1.1.2 Groups 6, 7
Register Groups 6 and 7 have multiple registers in each group. To read
or write each register, rst set the Group 0 Address Indirection Register
to the register number within the group, then write the group number to
the user interface address bits A[2:0]. After each access to these groups,
the Address Indirection Register auto-increments if the auto-increment
bit is set.
2.1.2
Reading or
Writing Multiple
Registers in a
Group
Register Groups 6 and 7 have more than one register in each group.
Each register can be accessed sequentially. To perform a sequential
access, rst initialize the address indirection register, then access the
appropriate group multiple times. Each time the group is accessed, the
address pointer is automatically incremented, allowing the user to step
through all the registers in sequence from an arbitrary start point.
Accessing addresses outside the range of addresses within the group is
not dened.
2.2
Group 0
Address
Indirection
Register
The Address Indirection Register is a read/write auto-incrementing reg-
ister, used as an index to registers within other groups. Writing to the reg-
ister sets its value. Reading the register returns its current value. The
register may optionally be congured to operate in an auto-increment or
auto-decrement mode.
Figure 2.1
Address Indirection
Register
AD
Auto Decrement
7, R/W
Accessing any register in Groups 6 and 7 causes the CI
to automatically decrement if the Auto Decrement bit is
set. CI will not automatically decrement if the AD bit is not
set.
AI
Auto Increment
6, R/W
Accessing any register in Groups 6 and 7 causes the CI
to automatically increment if the Auto Increment bit is set.
CI will not automatically increment if the AI bit is not set.
7654
0
AD
AI
CI