DSP Core Programming Model
6
-16
DSP56303 User’s Manual
6.6.3
Host Data Direction Register (HDDR)
The HDDR controls the direction of the data flow for each of the HI08 signals configured as
GPIO. Even when the HI08 functions as the host interface, its unused signals can be
configured as GPIO signals. For information on the HI08 GPIO configuration options, see
Section 6.2, Host Port Signals, on page 6-3. If Bit DRxx is set, the corresponding HI08
signal is configured as an output signal. If Bit DRxx is cleared, the corresponding HI08 signal
is configured as an input signal. Hardware and software reset clear the HDDR bits.
6.6.4
Host Data Register (HDR)
The HDR register holds the data value of the corresponding bits of the HI08 signals
configured as GPIO signals. The functionality of Dxx depends on the corresponding HDDR
bit (that is, DRxx).The host processor can not access the Host Data Register (HDR)
0
HRDF
0
Host Receive Data Full
Indicates that the host receive data register (HRX) contains data from the
host processor. HRDF is set when data is transferred from the
TXH:TXM:TXL registers to the HRX register. The host processor can also
clear HRDF using the initialize function.
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
DR15 DR14 DR13 DR12 DR11 DR10
DR9
DR8
DR7
DR6
DR5
DR4
DR3
DR2
DR1
DR0
Figure 6-8. Host Data Direction Register (HDDR) (X:$FFFFC8)
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Figure 6-9. Host Data Register (HDR) (X:$FFFFC8)
Table 6-10. HDR and HDDR Functionality
HDDR
HDR
DRxx
D
xx
GPIO Signal
1
Non-GPIO Signal
1
0
Read-only bit—The value read is the binary value of
the signal. The corresponding signal is configured as
an input.
Read-only bit—Does not contain significant data.
1
Read/write bit— The value written is the value read.
The corresponding signal is configured as an output
and is driven with the data written to Dxx.
Read/write bit— The value written is the value read.
1. Defined by the selected configuration.
Table 6-9. Host Status Register (HSR) Bit Definitions (Continued)
Bit Number
Bit Name
Reset Value
Description
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 ...