Signal and Transistor Descriptions
ARM DDI 0210C Copyright © 2001, 2004 ARM Limited. All rights reserved. A-11
RANGEOUT1
EmbeddedICE-RT RANGEOUT1
OAs RANGEOUT0 but corresponds to the EmbeddedICE-RT watchpoint
unit 1.
RSTCLKBS
Boundary scan Reset Clock
O When either the TAP controller state machine is in the RESET state or when
nTRST is LOW, then this is HIGH. This can be used to reset external
boundary-scan cells.
SCREG[3:0]
Scan chain register
O These reflect the ID number of the scan chain currently selected by the TAP
controller. These change on the falling edge of TCK when the TAP state
machine is in the UPDATE-DR state.
SDINBS
Boundary scan serial input data
O This provides the serial data for an external boundary-scan chain input. It
changes from the rising edge of TCK and is valid at the falling edge of TCK.
SDOUTBS
Boundary scan serial output data
IC Accepts serial data from an external boundary-scan chain output,
synchronized to the rising edge of TCK.
This must be tied LOW, if an external boundary-scan chain is not connected.
SEQ
Sequential address
O When the address of the next memory cycle is closely related to that of the
last memory access, this is HIGH.
In ARM state the new address can be for the same word or the next. In
THUMB state, the same halfword or the next.
It can be used, in combination with the low-order address lines, to indicate
that the next cycle can use a fast memory mode (for example DRAM page
mode) or to bypass the address translation system.
SHCLKBS
Boundary scan shift clock, phase
one
O Used to clock the master half of the external scan cells and follows TCK1
when in the SHIFT-DR state of the state machine and scan chain 3 is
selected. When not in the SHIFT-DR state or when scan chain 3 is not
selected, this clock is LOW.
SHCLK2BS
Boundary scan shift clock, phase
two
OAs SHCLKBS but follows TCK2 instead of TCK1.
This must be left unconnected, if an external boundary-scan chain is not
connected.
TAPSM[3:0]
TAP controller
state machine
O These reflect the current state of the TAP controller state machine. These bits
change on the rising edge of TCK.
See Figure B-2 on page B-5.
Table A-3 Signal descriptions (continued)
Name Type Description
To Next Page
Loading...
