Control and Status Registers
400
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Level 2 RAM (L2RAMW) Module
8.3.6 L2RAMW RAM Test Mode Control Register (RAMTEST)
The RAMTEST register, shown in
and described in
, controls the test mode of the
L2RAMW Module.
Figure 8-7. L2RAMW Module Test Mode Control Register (RAMTEST) (offset = 30h)
31
16
Reserved
R-0
15
9
8
7
6
5
4
3
0
Reserved
TRIGGER
TEST_MODE
Reserved
TEST_ENABLE
R-0
R/WP-0
R/WP-0
R-0
R/WP-5h
LEGEND: R/W = Read/Write; R = Read only; WP = Write in privileged mode only; -
n
= value after reset
Table 8-8. L2RAMW Module Test Mode Control Register (RAMTEST) Field Descriptions
Bit
Field
Value
Description
31-9
Reserved
0
Reads return 0. Writes have no effect.
8
TRIGGER
Test Trigger. This is an auto clear test trigger used to test the redundant address decode,
data merging mux, SECDED malfunction compare logic, and ECC checking logics. The
diagnostic test is executed when test mode is enabled and the test trigger is applied by
writing a 1 to this bit. The trigger is valid only if test mode is enabled, the correct mode is
configured in the TEST_MODE field, and all diagnostic error bits in the RAMERRSTATUS
register are in the cleared state. The trigger bit is auto clear after the test and has to be
written again for a new test.
7-6
TEST_MODE
Test Mode. This field selects either equality or inequality testing schemes for redundant
address decoding and SECDED malfunction diagnostics.
If TEST_MODE is set to 2h, equality check is done. The test stimulus stored in
RAMADDRDEC_VECT register is fed directly to both the channels of the comparator. If
the XOR of these two inputs
is not zero
, then UERR interrupt is generated and ADDE
flag is set in RAMERRSTATUS register.
If TEST_MODE is set to 1h, inequality check is done. The test stimulus stored in
RAMADDRDEC_VECT register is inverted and fed into one channel and the non-inverted
vector is fed into the other channel. If the XOR of these inputs
is zero
, then the UERR
interrupt is generated and ADDE flag is set in RAMERRSTATUS register.
5-4
Reserved
0
Reads return 0. Writes have no effect.
3-0
TEST_ENABLE
Test Enable. This is a 4-bit key to enable the redundant address decode, SECDED
malfunction, data merging mux and ECC checking diagnostics. If the test scheme is
enabled, then the compare logic uses the test vector inputs from the
RAMADDRDEC_VECT, DIAG_ECC, DIAG_DATA_VECTOR_L, and
DIAG_DATA_VECTOR_H registers. The functional path comparison is disabled when test
mode is enabled.
Ah
Test mode is enabled.
All other values
Test mode is disabled.