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Host Programmer Model
6
-28
DSP56303 User’s Manual
Table 6-17. Interface Status Register (ISR) Bit Definitions
Bit Number
Bit Name
Reset Value
Description
7
HREQ
0 (Hardware
and Software
reset)
1 (Individual
reset and
TREQ is set)
1 (Stop reset
and TREQ is
set)
Host Request
If HDRQ is set, the HREQ bit indicates the status of the external transmit
and receive request output signals (HTRQ and HRRQ). If HDRQ is
cleared, HREQ indicates the status of the external host request output
signal (HREQ). The HREQ bit is set from either or both of two conditions—
the receive byte registers are full or the transmit byte registers are empty.
These conditions are indicated by status bits: ISR RXDF indicates that the
receive byte registers are full, and ISR TXDE indicates that the transmit
byte registers are empty. If the interrupt source is enabled by the
associated request enable bit in the ICR, HREQ is set if one or more of the
two enabled interrupt sources is set.
HDRQ
HREQ
Effect
0
0
HREQ is cleared; no host processor
interrupts are requested.
0
1
HREQ is set; an interrupt is requested.
1
0
HTRQ and HRRQ are cleared, no host
processor interrupts are requested.
1
1
HTRQ or HRRQ are set; an interrupt is
requested.
6–5
0
Reserved. Write to 0 for future compatibility.
4
HF3
0
Host Flag 3
Indicates the state of HF3 in the HCR on the DSP side. HF3 can be
changed only by the DSP56303. Hardware and software reset clear HF3.
3
HF2
0
Host Flag 2
Indicates the state of HF2 in the HCR on the DSP side. HF2 can be
changed only by the DSP56303. Hardware and software reset clear HF2.
2
TRDY
1
Transmitter Ready
Indicates that TXH:TXM:TXL and the HRX registers are empty. If TRDY is
set, the data that the host processor writes to TXH:TXM:TXL is
immediately transferred to the DSP side of the HI08. This feature has
many applications. For example, if the host processor issues a host
command that causes the DSP56303 to read the HRX, the host processor
can be guaranteed that the data it just transferred to the HI08 is that being
received by the DSP56303. Hardware, software, individual, and stop
resets all set TRDY.
CAUTION:
TRDY = TXDE and HRDF
Содержание DSP56303
Страница 1: ...DSP56303 User s Manual 24 Bit Digital Signal Processor DSP56303UM AD Revision 1 January 2001 ...
Страница 52: ...JTAG OnCE Interface 2 22 DSP56303 User s Manual ...
Страница 114: ...General Purpose Input Output GPIO 5 10 DSP56303 User s Manual ...
Страница 212: ...GPIO Signals and Registers 8 26 DSP56303 User s Manual ...
Страница 268: ...Interrupt Equates A 22 DSP56303 User s Manual ...
Страница 306: ...Programming Sheets B 38 DSP56303 User s Manual ...
Страница 320: ...Index 14 DSP56303 User s Manual ...