CN8478 Datasheet, PDF (104/221 Pages) Conexant Systems, Inc – Multichannel Synchronous Communications Controller (MUSYCC)

5.0 Memory Organization
5.2 Descriptors
CN8478/CN8474A/CN8472A/CN8471A
Multichannel Synchronous Communications Controller (MUSYCC™)
5.2.2.4 Memory
Protection Descriptor
The memory protection function is not implemented. This function must be
disabled by clearing the PROTENBL bit in the Memory Protection Descriptor.
Table 5-11 lists the bit field and description of the Memory Protection Descriptor.
Table 5-11. Memory Protection Descriptor
Bit
Field
Name
Value
Description
31
PROTENBL
30:28
27:16
RSVD
PROTHI[11:0]
0
Memory Protection Disabled.
1
Memory Protection Enabled. Not supported.
0
Reserved.
Memory Protection High Address. Upper 12 bits (inclusive) of address for highest
memory location under protection.
15:12
RSVD
0
Reserved.
11:0 PROTLO[11:0]
Memory Protection Low Address. Upper 12 bits (inclusive) of the address for lowest
memory location under protection.
5.2.2.5 Port
Configuration Descriptor
The Port Configuration Descriptor defines how MUSYCC interprets and
synchronizes the transmit and receive bit streams associated with a port. There is
one descriptor per port; therefore, the descriptor is used for both transmit and
receive directions for a single port.
NOTE: When a port is being used in conjunction with another port —as is the case
when PORTMAP=1 or PORTMAP=2 (see Table 5-6, Global
Configuration Descriptor)—it is imperative that the unused port descriptor
be mapped identically to the used port descriptor. That is, if PORTMAP=1,
then the group 1/port 1 descriptor must be bit-for-bit identical with the
group 0/port 0 descriptor; and, the group 3/port 3 descriptor must be
bit-for-bit identical with the group 2/port 2 descriptor. In the case of
PORTMAP=2, then the group 1, 2, and 3 descriptors must be bit-for-bit
identical with the group 0/port 0 descriptor.
Table 5-12 details the Port Configuration Descriptor.
5-18
Conexant
100660E