ARM ARM7TDMI - Page 275

Differences Between Rev 3a and Rev 4
ARM DDI 0210C Copyright © 2001, 2004 ARM Limited. All rights reserved. C-5
• RANGEOUT1
• RANGEOUT0
• EXTERN1
• EXTERN0
• BUSEN
• DBGEN
• INSTRVALID.
The following pins are now no longer included in scan chain 0:
• IFEN
• CGENDBGACK
• DCTL
Scan chains 1, 2, 3, 4, and 8
Scan chains 1, 2, and 3 are unchanged.
Scan chains 4 and 8 are reserved for internal use by ARM Limited.
C.2.7 Change to pin positioning
Pin order remains the same, with only one new pin appearing at the upper left corner of
the device (see Enhancement to ETM interface on page C-4).
C.2.8 Increased number of metal layers
The ARM7TDMI Rev 4 requires four metal layers, compared to three for the
ARM7TDMI Rev 3a.
C.2.9 Increased power consumption
It is estimated that the ARM7TDMI Rev 4 will consume 10% less power than the
ARM7TDMI Rev 3a on the same process.