Motorola MPC8260 User Manual

33-8

MOTOROLA

The examples below show how SPMODE[LEN] is used to determine character length. To
help map the process, the conventions shown in Table 33-2 are used in the examples.

Once the data string image is determined, it is always transmitted byte by byte with the lsb
of the most-signiÞcant byte sent Þrst. For all examples below, assume the memory contains
the following binary image:

msb

ghij_klmn__opqr_stuv

lsb

with LEN=4 (data size=5), the following data is selected:

msb

xxxj_klmn__xxxr_stuv

lsb

with REV=0, the data string image is:

msb

j_klmn__r_stuv

lsb

the order of the string appearing on the line, a byte at a time is:

first

nmlk_j__vuts_r

last

with REV=1,the string has each byte reversed, and the data string image is:

msb

nmlk_j__vuts_r

lsb

the order of the string appearing on the line, one byte at a time is:

first

j_klmn__r_stuv

last

with LEN=7 (data size=8), the following data is selected:

msb

ghij_klmn__opqr_stuv

lsb

the data string is selected:

msb

ghij_klmn__opqr_stuv

lsb

with REV=0, the string transmitted, a byte at a time with lsb first is:

first

nmlk_jihg__vuts_rqpo

last

with REV=1, the string is byte reversed and transmitted, a byte at a time, with 

lsb first:

first

ghij_klmn__opqr_stuv

last

with LEN=0xC (data size=13), the following data is selected:

msb

ghij_klmn__xxxr_stuv

lsb

gÐv Binary 

symbols

x Deleted 

bit

__ 

1

1

Both __ and _ are used to aid readability.

Original byte boundary

_ 

Original 4-bit boundary.