IDT EJTAG System
EJTAG Test Access Port
79RC32438 User Reference Manual
20 - 54
November 4, 2002
Notes
Figure 20.20 Data Break on Store with Value Compare
In this example, the data breakpoint registers are set up as follows:
–
DBA0 = 0x0000 0200
–
DBM0 = 0
–
DBC0: BE = 1, NoLB = 1, NoSB = 0, BLM = 11112, BAI = 00112, ASIDuse = 0, other bits zero
Data Break on Store(s) to Halfword Range in Memory with Certain Value
In this example, the most significant halfword in a given memory range is altered, and the most signifi-
cant part of the halfword is written a certain value. The data word is illustrated below; the halfword for bits
31:16 is shaded. The store instructions shown in Figure 20.21 alter the shaded halfword and cause a break
if the breakpoint registers are set up as shown below.
Figure 20.21 Data Break on Store with Value Compare
In this example, the data breakpoint registers are set up as follows:
–
DBA0 = 0x0000 0200
–
DBM0 = 0x0000 00FC
–
DBV0 = 0xAA00 0000
DBC0: BE = 1, NoLB = 1, NoSB = 0, BLM = 01112, BAI = 00112, ASIDuse = 0, other bits zero
EJTAG Test Access Port
The overall features of the EJTAG Test Access Port (TAP) are:
Identification of device and EJTAG debug features accessed through the TAP
dmseg memory "emulation" (mapping dmseg processor accesses into probe transactions).
Reset handling allows debug exception immediately after reset
Debug interrupt request from probe
Low-power mode indications
Implementation-dependent processor and peripheral reset.
3
2
Break on Memory Address 0x0000 0200 bit 31:16, Little Endian
31
0
SW
SH
SB
SB
$2, 0x0000 0200
$2, 0x0000 0202
$2, 0x0000 0202
$2, 0x0000 0203
bytes_valid = 1111
2
bytes_valid = 1100
2
bytes_valid = 0100
2
bytes_valid = 1000
2
Break on Memory Address range 0x0000 0200 - 0x0000 02FC
Write to bits 31:16, bits 31:24 with value 0xAA, Little Endian
SW
SH
SB
SB
‘X’ denotes undefined value.
$2, 0x0000 0220
$2, 0x0000 0242
$2, 0x0000 0282
$2, 0x0000 02F3
$2=0xAAXX XXXX
$2=0xXXXX AAXX bytes_valid = 1100
2
$2=0xXXXX XXXX bytes_valid = 0100
2
$2=0xXXXX XXAA
bytes_valid = 1111
2
bytes_valid =
1000
2
3
2
31
0