Table 12-6 Relationship Of Fdoie And Fdobf; Fcop Data Saturation (Fsat)—Fcsr Bit 12 - Motorola DSP56305 User Manual

12.4.6.5 FCOP Data Output Interrupt Enable (FDOIE)—FCSR Bit 11
The FCOP Data Output Interrupt Enable (FDOIE) read/write control bit, when set,
enables the Data Output Interrupt. When FDOIE is cleared, the Data Output Interrupt is
disabled and the FDOBF status bit should be polled to determine if FDOR is full. The
following table describes the effect of the possible combined states of FDOIE and
FDOBF:
FDOIE FDOBF
0 0
0 1
1 0
1 1
DMA transfer is enabled if a DMA channel is activated and allocated for FCOP Data
Output Buffer Full (FDOBF is set). FDOR should be read by the interrupt routine or by
the DMA transfer, but not both; thus it is highly recommended to enable either the
interrupt or DMA, but not both.
12.4.6.6 FCOP Data Saturation (FSAT)—FCSR Bit 12
The FCOP Data Saturation (FSAT) read-only status bit indicates, when set, that overflow
or underflow occurred in the MAC result. FSAT is a sticky status bit, set by hardware
and cleared by hardware reset, software reset, or FCOP individual reset. When overflow
occurs, the result will be saturated to the most positive number $7FFF. When underflow
occurs, the result will be saturated to the most negative number $8000.
MOTOROLA

Table 12-6 Relationship of FDOIE and FDOBF

Data Output Interrupt
(FDOR) is not full. Do not read from FDOR.
Data Output Interrupt
(FDOR) is full. DMA read from FDOR is possible.
Data Output Interrupt
(FDOR) is not full. Do not read from FDOR.
Data Output Interrupt
(FDOR) is full. FCOP requests a Data Output Interrupt service
from the DSP56300 core. Interrupt read from FDOR is possible.
DSP56305 User's Manual
Effect
Data Output Register
is disabled. FCOP
Data Output Register
is disabled. FCOP
Data Output Register
is enabled. FCOP
Data Output Register
is enabled. FCOP
Filter Co-Processor
Programming Model
12-12