MAS3587F Micronas, MAS3587F Datasheet - Page 25

• Manufacturer Part Number: MAS3587F
• Description: MPEG Layer 3 Audio Encoder/Decoder
• Manufacturer: Micronas

ADVANCE INFORMATION
3.3.1.1. Run and Freeze
The Run command causes the start of a program part at address a = (a3,a2,a1,a0). Since nibble a3 is also the com-
mand code (see Table 3–4), it is restricted to values between 0 and 3.
If the start address is 1000
(see Table 3–5 on page 32), the MAS 3587F continues execution with a custom program already downloaded to this
area.
Example 1: Start program execution at address 345
<DW 68 03 45>
Example 2: Start execution of a downloaded code at address 3000
<DW 68 30 00>
Freeze is a special run command with start address 0. It suspends all normal program execution. The operating sys-
tem will enter an idle loop so that all registers and memory cells can be watched. This state is useful for operations
like downloading code or contents of memory cells because the internal program cannot overwrite these values.
This freezing will be required if alternative software is downloaded into the internal RAM of the MAS 3587F.
Freeze has the following I
<DW 68 00 00>
3.3.1.2. Read Register (Code A
Some registers (r = r1,r0 in the figure above) are direct control inputs for various hardware blocks, others control the
internal program flow. In contrast to memory cells, registers cannot be accessed as a block but must always be
addressed individually.
Example:
Read the content of the PIO data register (C8
<DW 68 ac 80>
<DW 69 <DR
Micronas
1) send command
2) get register value
S
S
S
DW
DW
DW
W
W
W
xx xd dd
A
A
A
$68
$68
$68
x,x
2
C protocol:
dd>
hex
W
W
W
A
hex
a < 3FFF
A
A
A
x,d4
)
a3
S
define register
and read
a,r1
,a2
W
hex
DR
hex
A
A
A
and the respective RAM area has been configured as program RAM
):
W
a1,a0
d3,d2
r0,0
hex
A
:
W
W
A
A
A
d1,d0
P
P
hex
:
W
N
P
MAS 3587F
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