Sundance SMT310 v.1.6 - Manual (Page 32)

User Manual (QCF42); Version 3.0, 8/11/00; © Sundance Multiprocessor Technology Ltd. 1999
A0..A30
DSP’s global Bus address lines
D0..D31
DSP’s global Bus data lines
IIOF0, IIOF1 & IIOF2
DSP’s Interrupt signals. These are open collector signals on the SMT310. They can
be driven by the DSP to generate an interrupt to the host, or they can be driven by
the host to interrupt the DSP.
In the timing diagram below all signals change relative to the rising LCLK signal. This
signal is the H1 clock signal of the DSP when using the DSP global bus in
synchronous mode (see SMT335 User Guide).
LCLK
STRB1
TIMReq FIFO Full
STAT[1.3]
RDY1
STA 0 T
AE E /D
A[30..0]
D[31..0]
Figure 6 : Timing diagram for DSP local bus access
* LCLK Period =30nS, frequency is 33MHz.
The DSP initiates a global bus R/W by asserting the STRB1 low and STAT[1:3}
change (see TIM Spec for details of STAT[1..3] details). Once the arbitration unit
detects this, it waits for the last cycle of the Local bus to be completed by the PCI
Bridge, before allowing the DSP to become Bus Master. Once the DSP is Master the
arbitration unit drives AE and DE low to enable the DSP’s address and data lines.
RDY1 is driven low by the arbitor to indicate to the DSP, on the next rising LCLK, that
the data packet has been transferred. If the input FIFO (256 Words Deep) becomes