summaryrefslogtreecommitdiff
path: root/doc/README.mpc83xx.ddrecc
diff options
context:
space:
mode:
authorStefan Roese <sr@denx.de>2007-08-15 14:51:27 +0200
committerStefan Roese <sr@denx.de>2007-08-15 14:51:27 +0200
commitd61ea14885631e58a25feaa81ee82eb464c62d6a (patch)
tree27927975039d0a15e6c6d4dfe8f765a76a12820a /doc/README.mpc83xx.ddrecc
parent3ba4c2d68f6541db4677b4aea12071f56e6ff6e6 (diff)
parent594e79838ce5078a90d0c27abb2b2d61d5f8e8a7 (diff)
downloadu-boot-imx-d61ea14885631e58a25feaa81ee82eb464c62d6a.zip
u-boot-imx-d61ea14885631e58a25feaa81ee82eb464c62d6a.tar.gz
u-boot-imx-d61ea14885631e58a25feaa81ee82eb464c62d6a.tar.bz2
Merge with git://www.denx.de/git/u-boot.git
Diffstat (limited to 'doc/README.mpc83xx.ddrecc')
-rw-r--r--doc/README.mpc83xx.ddrecc154
1 files changed, 154 insertions, 0 deletions
diff --git a/doc/README.mpc83xx.ddrecc b/doc/README.mpc83xx.ddrecc
new file mode 100644
index 0000000..0029f08
--- /dev/null
+++ b/doc/README.mpc83xx.ddrecc
@@ -0,0 +1,154 @@
+Overview
+========
+
+The overall usage pattern for ECC diagnostic commands is the following:
+
+ * (injecting errors is initially disabled)
+
+ * define inject mask (which tells the DDR controller what type of errors
+ we'll be injecting: single/multiple bit etc.)
+
+ * enable injecting errors - from now on the controller injects errors as
+ indicated in the inject mask
+
+IMPORTANT NOTICE: enabling injecting multiple-bit errors is potentially
+dangerous as such errors are NOT corrected by the controller. Therefore caution
+should be taken when enabling the injection of multiple-bit errors: it is only
+safe when used on a carefully selected memory area and used under control of
+the 'ecc testdw' 'ecc testword' command (see example 'Injecting Multiple-Bit
+Errors' below). In particular, when you simply set the multiple-bit errors in
+inject mask and enable injection, U-Boot is very likely to hang quickly as the
+errors will be injected when it accesses its code, data etc.
+
+
+Use cases for DDR 'ecc' command:
+================================
+
+Before executing particular tests reset target board or clear status registers:
+
+=> ecc captureclear
+=> ecc errdetectclr all
+=> ecc sbecnt 0
+
+
+Injecting Single-Bit Errors
+---------------------------
+
+1. Set 1 bit in Data Path Error Inject Mask
+
+=> ecc injectdatahi 1
+
+2. Run test over some memory region
+
+=> ecc testdw 200000 10
+
+3. Check ECC status
+
+=> ecc status
+...
+Memory Data Path Error Injection Mask High/Low: 00000001 00000000
+...
+Memory Single-Bit Error Management (0..255):
+ Single-Bit Error Threshold: 255
+ Single Bit Error Counter: 16
+...
+Memory Error Detect:
+ Multiple Memory Errors: 0
+ Multiple-Bit Error: 0
+ Single-Bit Error: 0
+...
+
+16 errors were generated, Single-Bit Error flag was not set as Single Bit Error
+Counter did not reach Single-Bit Error Threshold.
+
+4. Make sure used memory region got re-initialized with 0x0123456789abcdef
+
+=> md 200000
+00200000: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200010: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200020: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200030: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200040: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200050: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200060: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200070: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200080: deadbeef deadbeef deadbeef deadbeef ................
+00200090: deadbeef deadbeef deadbeef deadbeef ................
+
+Injecting Multiple-Bit Errors
+-----------------------------
+
+1. Set more than 1 bit in Data Path Error Inject Mask
+
+=> ecc injectdatahi 1
+=> ecc injectdatalo 1
+
+2. Run test over some memory region
+
+=> ecc testword 200000 1
+
+3. Check ECC status
+
+=> ecc status
+...
+Memory Data Path Error Injection Mask High/Low: 00000001 00000001
+...
+Memory Error Detect:
+ Multiple Memory Errors: 0
+ Multiple-Bit Error: 1
+ Single-Bit Error: 0
+...
+
+The Multiple Memory Errors flags not set and Multiple-Bit Error flags are set.
+
+4. Make sure used memory region got re-initialized with 0x0123456789abcdef
+
+=> md 200000
+00200000: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200010: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200020: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200030: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200040: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200050: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200060: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200070: 01234567 89abcdef 01234567 89abcdef .#Eg.....#Eg....
+00200080: deadbeef deadbeef deadbeef deadbeef ................
+00200090: deadbeef deadbeef deadbeef deadbeef ................
+
+
+Test Single-Bit Error Counter and Threshold
+-------------------------------------------
+
+1. Set 1 bit in Data Path Error Inject Mask
+
+=> ecc injectdatahi 1
+
+2. Enable error injection
+
+=> ecc inject en
+
+3. Let u-boot run for a with Single-Bit error injection enabled
+
+4. Disable error injection
+
+=> ecc inject dis
+
+4. Check status
+
+=> ecc status
+
+...
+Memory Single-Bit Error Management (0..255):
+ Single-Bit Error Threshold: 255
+ Single Bit Error Counter: 199
+
+Memory Error Detect:
+ Multiple Memory Errors: 1
+ Multiple-Bit Error: 0
+ Single-Bit Error: 1
+...
+
+Observe that Single-Bit Error is 'on' which means that Single-Bit Error Counter
+reached Single-Bit Error Threshold. Multiple Memory Errors bit is also 'on', that
+is Counter reached Threshold more than one time (it wraps back after reaching
+Threshold).