Miscellaneous registers (Misc)
RM0082
246/844
Doc ID 018672 Rev 1
[14]
DDR_EN_PAD
-
It contains the value decided in the external pad
DDR2_EN to select DDR (Low Power) or DDR2 (RO)
1’b0: DDR2
1’b1: DDR Low Power
[13]
REFSSTL
1’h1
Internal/External SSTL common reference voltage
definition:
1’b0: Internal reference voltage
1’b1: External reference voltage to be applied on
DDR_MEM_REF signal
[12]
GATE_OPEN_mode
1’h1
It selects the internal (1) or external (0) gate open
mode. It is connected to stp_asic IP.
[11]
RFU
-
Reserved for future use (Write don’t care - Read return
zeros).
[10]
ENZI
1’h0
Input buffer enable. Active low, connected to ENZI of
all the pads.
[09]
DQS_PDN_sel
1’h1
DQS Pull down. It is connected to PDCLK of SSTL
differential pads.
[08]
DQS_PU_sel
1’h0
DQS pull up, it is connected to PUCLK of SSTL
different pads.
[07]
CLK_PDN_sel
1’h1
Programmable CLK Pull down functionality connected
with both PDCLK and PCLKB signals of SSTL
different pads (ref. Pull-up/down configuration table)
[06]
CLK_PU_sel
1’h0
Programmable CLK Pull up functionality connected
with both PUCLK and PUCLKB signal of SSTL
different pads (ref. Pull-up/down configuration table)
[05]
PDN_sel
1’h1
Enable active Pull Down for SE SSTL pads (ref. next
table)
Pull/up down configuration table
Pull-up
Pull-Down
Description
0
1
Pull-up/down not
actives
1
1
Active pull-up
0
0
Active pull-down
1
0
Forbidden
[04]
PU-sel
1’h0
Pull up activation for SE SSTL pads (ref. Pull-up/down
configuration table)
Table 182.
DDR_PAD register bit assignments (continued)
DDR_PAD Register
0x0F0
Bit
Name
Reset
Value
Description