TOSHIBA
TMPR3904F Rev. 2.0
47
7.5.2
Release of bus ownership
The external bus master releases the bus ownership for two reasons:
Because the bus ownership is no longer necessary
Because of the BUSREL*.
(1) Release of the bus ownership because it is no longer necessary
When the bus ownership that has been kept after having been granted
becomes unnecessary, the external bus master deasserts the BUSREQ* and
HAVEIT* to return the bus ownership to the TX3904.
The following diagram shows the timing of releasing the bus ownership when it
is no longer necessary:
S Y S C L K
B U S R E Q *
B U S G N T *
H A V E I T *
B U S R E L *
T 1 T 2 T 3 T 4 T 5
T X 3 9 0 4
C y c l e
D e a d
C y c l e
E x t e r n a l B u s
M a s t e r C y c l e
T1 The external bus master has the bus ownership.
T2 The external bus master deasserts the BUSREQ* and HAVEIT* because the
bus ownership is no longer necessary.
T3 Having acknowledged that the BUSREQ* is high, the TX3904 deasserts the
BUSGNT*.
Summary of Contents for TMPR3904F
Page 1: ...Users Manual 32bit RISC Microprocessor TX39 family TMPR3904F Rev 2 0 Jan 12 1998 ...
Page 2: ......
Page 9: ...Users Manual 01 1 INTRODUCTION 1 1 Overview ...
Page 11: ...Users Manual 03 1 3 Kind of accessing by the TX3904 ...
Page 12: ...Users Manual 04 1 4 Precautions in the TMPR3904F specification Don t set Don t use ...
Page 13: ...Users Manual 05 Do not use ...
Page 14: ...Users Manual 06 ...
Page 15: ...Users Manual 7 2 FEATURES n n n n n n n n n n n n n ...
Page 16: ...Users Manual 8 ...
Page 18: ...Users Manual 10 ...
Page 19: ...Users Manual 11 4 PINS 4 1 Positions of Pins ...
Page 20: ...Users Manual 12 ...
Page 21: ...Users Manual 13 4 2 Functions of Pins ...
Page 22: ...Users Manual 14 ...
Page 23: ...Users Manual 15 ...
Page 24: ...Users Manual 16 ...
Page 26: ...Users Manual 18 5 2 Register Map ...
Page 27: ...Users Manual 19 ...
Page 28: ...Users Manual 20 ...
Page 30: ...Users Manual 22 5 3 2 PIO2 and PIO1 ...
Page 32: ...Users Manual 24 5 3 4 Connection of external bus master 5 3 5 INT 7 0 active status clear ...
Page 33: ...Users Manual 25 5 3 6 INT 7 0 active status set up ...
Page 34: ...Users Manual 26 ...
Page 123: ...TOSHIBA TMPR3904F Rev 2 0 115 26 ...
Page 169: ...TOSHIBA TMPR3904F Rev 2 0 161 26 ...
Page 203: ...TOSHIBA TMPR3904F Rev 2 0 195 ...
Page 230: ......