. 6.28.
/ (TCR). 24- TCR , , ( = 1), . TCR , ( + 1) . ( = 0) TCR, , , ( = 1). 4 5 TCR .
/ (TCSR). 24- . .
( 0).
. 1 , , TCR, . .
(TIE- 1).
1 0 . .
(INV- 2).
IO.
IO INV = 0, λ 1 IO . INV = 1, 1 0.
IO INV = 1, . INV = 0, .
4 INV , ( ) .
5 INV , .
/ , , / IO (INV = 1), (INV = 0).
.
(0-2 - 3-5).
, IO (. 6.18).
/ (GPIO - 6).
2 0 , IO /, DIR. .
(TS - 7).
, , . /. . .
(DIR - 8).
IO, /. DIR = 1, IO - , - .
|
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(DI 9.
IO , DI . .
(DO - 10).
IO , DO IO. .
.
.
0 ( , , ). ( = 1), , TCR. DSP, (CLK/2). , TS 1 . TCR , ( = 0).
1 ( , , ). ( = 1), , TCR. DSP, (CLK/2). , TS 1 . IO , INV. TCR , ( = 0).
3 ( , , ). ( =1), , TCR. DSP, (CLK/2). , TS 1 . IO . INV. TCR , ( = 0).
4 ( ). . ( = 1), DSP, . IO . , S 1 , TIE = 1, . TCR . , . INV , .
5 ( ). DSP, . , IO , TCR, . TS 1 , . TCR . INV , : 0 1 (INV = 0) 1 0 (INV = 1).
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6 ( , ). , , TCR. IO. TCR. , TS 1 . , .
7 ( , ). , , TCR. IO. , TS 1 . , . INV , : λ 1(INV = 0) 1 0 (INV = 1).
WAIT .
/
15 / , 8- host-. . 6.29. / , . host- .
/ , 15 /. (, X:$FFED), (PBDDR, X:$FFE2) (PBD, X:FFE4). PBDDR PBD 24 , 15 . 1 PBDDR , , - . 1 0 , host-, /.
. 6.30.
Host- (HI)
HI. HI-8- , , host-.
Host- , , DSP , . HI - : , host-, , DSP (. 6.31).
HI :
: 8 / - ; 1,71 / - ().
(15): 0-7 - ; 0-2 - ; HR/-.W - /; -.HEN - ; -iHREQ - ; -.HACK - .
Host- DSP. DSP HI , 24- . DSP HI , . , .
. HI , /.