Datasheet
T1 Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 Td0 Td1T0 Td2
t
PAR_ALERT_ON
DES
1
ERROR
2
DES
1
DES
5
CK#
CK
NOTE 1. Deselect command only allowed.
NOTE 2. Error could be Precharge or Activate.
NOTE 3. Normal operation with parity latency (CA Parity Persistent Error Mode disable). Parity checking is off until Parity Error Status bit cleared.
NOTE 4. Command execution is unknown the corresponding DRAM internal state change may or may not occur. The DRAM Controller should consider
both cases and make sure that the command sequence meets the specifications.
NOTE 5. Deselect command only allowed CKE may go high prior to Td2 as long as DES commands are issued.
t
PAR_ALERT_PW
1
t
RP
t
CPDED
DES
REF
4
DES
5
Command execution unknown
ERROR
2
DES
1
Command not executed
VALID
3
Command executed
t≧
2nCK
t
IS
DES
5
DES
REF
4
VALID
3
Td3 Te0 Te1
t
IS
t
IH
CKE
CMD/
ADDR
ALERT#
DON'T CARETIME BREAK
Figure 57. CA Parity Error Checking - PDE/PDX
T1 Ta0 Ta1 Tb0 Tb1 Tc0 Tc1 Td0 Td1T0 Td2
t
PAR_ALERT_ON
DON'T CARETIME BREAK
ERROR
2
DES
1,5
DES
1
DES
6
CK#
CK
NOTE 1. Deselect command only allowed.
NOTE 2. SelfRefresh command error. DRAM masks the intended SRE command enters Precharge Power Down.
NOTE 3. Normal operation with parity latency(CA Parity Persistent Error Mode disable). Parity checking is off until Parity Error Status bit cleared.
NOTE 4. Controller can not disable clock until it has been able to have detected a possible C/A Parity error.
NOTE 5. Command execution is unknown the corresponding DRAM internal state change may or may not occur. The DRAM Controller should
consider both cases and make sure that the command sequence meets the specifications.
NOTE 6. Deselect command only allowed CKE may go high prior to Tc2 as long as DES commands are issued.
t
PAR_ALERT_PW
1
t
RP
t
CPDED
DES
1,5
DES
6
Command execution unknown
ERROR
2
DES
1
Command not executed
VALID
3
Command executed
t 2nCK
t
IS
DES
6
DES
5
VALID
3
Td3 Te0 Te1
t
IS
t
IH
CKE
CMD/
ADDR
ALERT#
DES
REF
5
t
XP+PL
4
Figure 58. CA Parity Error Checking - SRE Attempt
AS4C256M16D4
Confidential
- 69 of 201 -
Rev.1.0 Aug.2019