Motorola MSC8101 ADS User's Guide Page 213

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Configure the Channels
Multi-Channel Controllers (MCCs) 10-11
GRFTHR and GRFCNT. Two parameters relating to the reception of frames.
GRFTHR is a threshold value after which an interrupt is generated.
XTRABASE. Defines the offset in the dual-port RAM (DPRAM) that points to the
location holding the extra channel-specific parameters. Each channel’s extra
parameters are stored in order contiguously from this offset. (Offset 0x3800 is used
in this example.)
The following parameters relate to interrupt queue set-up and handling:
TINTBASE. Defines the Tx circular interrupt table location. In this driver example,
the interrupt tables are held in external memory; however, they can be held in
DPRAM.
RINTBASE. Points to the receive circular table location. This example uses RINT
Table 0.
Before the interrupts are enabled, the Rx and Tx temporary interrupt queue locations
should be initialized to zero, with the wrap bit set in the last entry.
10.3.2 Set Up the MCC Configuration and Control Registers
Part of the global setup is to initialize the three main MCC control registers:
MCCFx. Defines the mapping of MCC channel blocks to a TDM pin interface.
Table 10-4 shows the TDM-to-MCC usage available for the MSC8101. The 128
channels on each MCC are split into four su/jointfilesconvert/467811/bgroups, each of which can be routed to
a particular TDM. All MCC1 channels must be routed through TDMA. The MCC2
su/jointfilesconvert/467811/bgroups are routed to one of three TDMs (TDMB, TDMC, or TDMD). All
channels within a su/jointfilesconvert/467811/bgroup must be routed to the same TDM, though different
su/jointfilesconvert/467811/bgroups can be routed to the same or different TDMs (see Table 10-4 for
details). The transmit and receive data flow is controlled by the programmable
SIRAM and the respective MCCF2[0-7] register, which routes the data to the
specified channels. The TDM group channel assignments made in the respective
MCCF register must be coherent with the SI register programming. The example
driver code configures 32 MCC2 channels in the range 160–191 for TDMB by
setting the MCCF2 register to 0x10.
.
Table 10-4. MCC TDM Usage in MSC8101
SIRAM1 (MCC1) SIRAM2 (MCC2)
MCC Su/jointfilesconvert/467811/bgroup A B C D A
BCD
MCC Channel 0–31 32–63 64–95 96–127 128–159
160–191 192–231 231–256
Usable TDM YesNoNoNoNo
Yes Yes Yes
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