SAA7391H Philips Semiconductors, SAA7391H Datasheet - Page 30

• Manufacturer Part Number: SAA7391H
• Description: ATAPI CD-R block encoder/decoder
• Manufacturer: Philips Semiconductors

Philips Semiconductors
Table 41 Description of the MCK_CON register bits (note 1)
Note
1. The bits in this register control the use of the MCK pin as an output to clock a CD-DSP. The division ratios chosen
7.3.5
This function is provided for the user to move and copy
blocks of RAM. Two pointer sets are provided. The second
of these is for the semi-automatic subcode copying
function of the subcode in the block. It is independent of
the first copy register set, which is available for e.g. audio
copying needed in the PLAY AUDIO function with the
SAA7391, and for subcode copying when recording.
When started, the copy process will copy the
COPYCOUNT register bytes from the ‘FROM’ pointers to
the ‘TO’ pointers. A copying process may be stopped
during its operation by writing to the ‘copyend’ bit.
7.3.5.1
When enabled, the newly received subcode will be
automatically transferred to the current host segment in
RAM.
1997 Aug 01
1 and 0
ATAPI CD-R block encoder/decoder
BIT
are suitable for the SAA7335 or CDR60 devices. If the MCK pin is not being used then it should be pulled HIGH for
correct selection of the internal multimedia clocks.
3
2
M
EMORY
Automatic copying of received
subcode-to-data block
mckxtal
NAME
mckoe
div
-
TO
-
MEMORY BLOCK COPY FUNCTION
VALUE
00
01
10
11
0
1
0
1
MCK reference is system clock (default)
MCK reference is the CRIN pin
MCK pin is 3-state, an input to the MM block (default)
MCK pin is output
MCK reference is divided by 2 (default)
MCK reference is divided by 1.5
MCK reference is divided by 1
MCK reference is divided by 4
30
The only register that is user programmable in the subcode
copying engine is the COPYFROM2OFFSET pointer.
The ‘COPYFROM2OFFSET’ pointer is set up by the
sub-CPU to point into the subcode input FIFO. It points at
the first byte of subcode to be copied into the current host
data block. Once triggered, this copy is automatically
set-up to correctly transfer the next block of subcode
correctly without host intervention.
Copying of the subcode in the opposite direction is
performed by the sub-CPU commanding an interleaved
copy of data using the user block copy registers. This does
not have to be as fast as the recorder function is only
specified to n
DESCRIPTION
8. Hence it is not automated.
Objective specification
SAA7391