Motorola MPC8260 User Manual

27-12

MOTOROLA

RSTATE high-byte Þelds are described in Table 27-6. 

Bits

0

1

2

3

4

5

6

7

Field

Reset

Ñ

R/W

R/W

Addr

0x20

0Ð1

Ñ

Reserved, should be cleared.

2

Global. Setting GLB activates snooping (only the 60X bus can be snooped, this parameter is ignored 
for local bus transactions). 

3Ð4

Byte ordering. Set BO to select the required byte ordering for the buffer. If BO is changed on-the-ßy, 
it takes effect at the beginning of the next frame or at the beginning of the next BD. 
00 Reserved
01 PowerPC little-endian. 
1x  Big-endian 

5

Transfer code. Contains the transfer code value of TC[2], used during this SDMA channel memory 
access. TC[0Ð1] is driven with a 0b11 to identify this SDMA channel access as a DMA-type access. 

6

Data bus indicator. 
The transfers to data buffers are handled by the:
0 60x bus SDMA 
1 Local bus SDMA 

7

BD and interrupt circular tables bus indicator.
The transfers to/from BD and interrupt circular tables are handled by the:
0 60x bus SDMA 
1 Local bus SDMA 
Note that the following restrictions result from the fact that there is a common bus selection bit for 
BDs and interrupt circular tables:
¥

The RxBDs of all the channels that use a particular interrupt table must reside on the same bus 
(60x or local).

¥

All TxBDs must reside on the same bus (60x or local).

0x00

Word

Tx internal state. To start a transmitter channel the user must write to TSTATE 
0xHH80_0000. HH is the TSTATE high byte described in Section 27.6.1, ÒInternal 
Transmitter State (TSTATE).Ó