AN3099

DDR IBIS model selection

Doc ID 16605 Rev 1

7/13

2

DDR IBIS model selection

The I/O signals of the DDR interface form three main groups.

Each group has one set of models associated.

Please refer to the following table for the I/O signals and the associated model name.

Each model group name contains a set of models depending upon the value of the 8 bits

xxxxxxxx for the selected DDR_MEM_* signal.

Please refer to the SPEAr3xx user manual for the following register name:

●

DDR_PAD

●

MEMCTL_AHB_SET_02

Table 2.

Relation between the DDR block signals and the used model

DDR block signal name

IBIS model group name

DDR_MEM_CLKP &

DDR_MEM_CLKN

DDR_MEM_DQS_0 &

nDDR_MEM_DQS_0

DDR_MEM_DQS_1 &

nDDR_MEM_DQS_1

BDCLK_R_IN_xxxxxxxx

xxxxxxxx = DDR PRGA PRGB ZOUT MDZI ODTA ODTB

ODEN

DDR_MEM_ADD[14,12,10,8,6,4,2,0]

DDR_MEM_DQ[15,13,11,9,6,4,2,0]

DDR_MEM_GATE_0

DDR_MEM_DM_1

DDR_MEM_CLKEN

DDR_MEM_CS_1

DDR_MEM_ODT_1

DDR_MEM_BA_1

DDR_MEM_CAS

BDRES_GNDE_xxxxxxx

xxxxxxxx = ZOUT PROGA PROGB MDZI DDR ODEN

ODTA ODTB

DDR_MEM_ADD[13,11,9,7,5,3,1]

DDR_MEM_DQ[14,12,10,8,7,5,3,1]

DDR_MEM_GATE_1

DDR_MEM_DM_0

DDR_MEM_CS_0

DDR_MEM_ODT_0

DDR_MEM_BA_0

DDR_MEM_BA_2

DDR_MEM_RAS

DDR_MEM_WE

BDRES_VDDE_xxxxxxx

xxxxxxxx = ZOUT PROGA PROGB MDZI DDR ODEN

ODTA ODTB