Chapter 7 External Bus Controller
7-46
7.5.9
External ACK Mode Access (32-bit Bus)
Note 1: The TX4937 sets the ACK
*
signal to High Impedance in the S1 State.
Note 2: External devices drive the ACK
*
signal to Low (assert the signal) by the ES1 State.
Note 3: External devices drive the ACK
*
signal to High (deassert the signal) in the ES2
State. If an external device is late in asserting ACK
*
, then the Wait State is inserted
for the amount of time the external device is late. If a certain condition is met, it is
okay for the ACK
*
signal to be driven to Low for 1 clock cycle or more. See 7.3.7.4
ACK
*
Input Timing (External ACK Mode) for more information.
Figure 7.5.23 1-word Single Write (0 Wait, SHWT=0, External ACK
*
, 32-bit Bus)
Figure 7.5.24 1-word Single Read (0 Wait, SHWT=0, External ACK
*
, 32-bit Bus)
SYSCLK
CE
*
ADDR[19:0]
ACE
*
OE
*
/BUSSPRT
*
SWE
*
BWE
*
BE
*
DATA[31:0]
S1
ES2
ES1
S2
S3
ACK
*
f 0
f
f
SYSCLK
CE
*
ADDR[19:0]
ACE
*
OE
*
/BUSSPRT
*
SWE
*
BWE
*
BE
*
DATA[31:0]
S1
ES2
ES1
ES3
S3
S2
ACK
*
0
f
f
f
0
f
Summary of Contents for TX49 TMPR4937
Page 1: ...64 Bit TX System RISC TX49 Family TMPR4937 Rev 2 0 ...
Page 4: ......
Page 13: ...Table of Contents ix TMPR4937 Revision History 1 ...
Page 14: ...Table of Contents x ...
Page 15: ...Handling Precautions ...
Page 16: ......
Page 18: ...1 Using Toshiba Semiconductors Safely 1 2 ...
Page 40: ...3 General Safety Precautions and Usage Considerations 3 18 ...
Page 42: ...4 Precautions and Usage Considerations 4 2 ...
Page 43: ...TMPR4937 2005 3 Rev 2 0 ...
Page 44: ......
Page 52: ...Chapter 1 Overview and Features 1 6 ...
Page 156: ...Chapter 7 External Bus Controller 7 56 ...
Page 491: ...Chapter 16 Removed 16 1 16 Removed ...
Page 492: ...Chapter 16 Removed 16 2 ...
Page 493: ...Chapter 17 Removed 17 1 17 Removed ...
Page 494: ...Chapter 17 Removed 17 2 ...
Page 495: ...Chapter 18 Removed 18 1 18 Removed ...
Page 496: ...Chapter 18 Removed 18 2 ...
Page 497: ...Chapter 19 Removed 19 1 19 Removed ...
Page 498: ...Chapter 19 Removed 19 2 ...
Page 506: ...Chapter 20 Extended EJTAG Interface 20 8 ...
Page 530: ...Chapter 22 Pinout and Package Information 22 10 ...
Page 542: ...Chapter 24 Parts Number when Ordering 24 2 ...