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Host Interface (HI08)
2
-10
DSP56303 User’s Manual
2.7
Host Interface (HI08)
The HI08 provides a fast, parallel data-to-8-bit port that can directly connect to the host bus.
The HI08 supports a variety of standard buses and can directly connect to a number of
industry-standard microcomputers, microprocessors, DSPs, and DMA hardware.
2.7.1
Host Port Usage Considerations
Careful synchronization is required when the system reads multiple-bit registers that are
written by another asynchronous system. This is a common problem when two asynchronous
systems are connected (as they are in the Host port). The considerations for proper operation
are discussed in Table 2-10.
MODC/IRQC
Input
Input
Mode Select C/External Interrupt Request C—Selects the initial chip
operating mode during hardware reset and becomes a level-sensitive
or negative-edge-triggered, maskable interrupt request input during
normal instruction processing. MODA, MODB, MODC, and MODD
select one of sixteen initial chip operating modes, latched into OMR
when the RESET signal is deasserted.
Internally synchronized to CLKOUT. If IRQC is asserted synchronous
to CLKOUT, multiple processors can be re-synchronized using the
WAIT instruction and asserting IRQC to exit the Wait state.
MODC/IRQC can tolerate 5 V.
MODD/IRQD
Input
Input
Mode Select D/External Interrupt Request D—Selects the initial chip
operating mode during hardware reset and becomes a level-sensitive
or negative-edge-triggered, maskable interrupt request input during
normal instruction processing. MODA, MODB, MODC, and MODD
select one of sixteen initial chip operating modes, latched into OMR
when the RESET signal is deasserted.
Internally synchronized to CLKOUT. If IRQD is asserted synchronous
to CLKOUT, multiple processors can be re-synchronized using the
WAIT instruction and asserting IRQD to exit the Wait state.
MODD/IRQD can tolerate 5 V.
Table 2-10. Host Port Usage Considerations
Action
Description
Asynchronous read of receive
byte registers
When reading the receive byte registers, Receive register High (RXH), Receive register
Middle (RXM), or Receive register Low (RXL), the host interface programmer should use
interrupts or poll the Receive Register Data Full (RXDF) flag that indicates data is
available. This assures that the data in the receive byte registers is valid.
Table 2-9. Interrupt and Mode Control (Continued)
Signal Name
Type
State During
Reset
Signal Description
Summary of Contents for DSP56303
Page 1: ...DSP56303 User s Manual 24 Bit Digital Signal Processor DSP56303UM AD Revision 1 January 2001 ...
Page 52: ...JTAG OnCE Interface 2 22 DSP56303 User s Manual ...
Page 114: ...General Purpose Input Output GPIO 5 10 DSP56303 User s Manual ...
Page 212: ...GPIO Signals and Registers 8 26 DSP56303 User s Manual ...
Page 268: ...Interrupt Equates A 22 DSP56303 User s Manual ...
Page 306: ...Programming Sheets B 38 DSP56303 User s Manual ...
Page 320: ...Index 14 DSP56303 User s Manual ...