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MSC8154E Datasheet, PDF (27/68 Pages) Freescale Semiconductor, Inc – Quad-Core Digital Signal Processor with Security
Electrical Characteristics
2.5.1.2 DDR3 (1.5V) SDRAM DC Electrical Characteristics
Table 7 provides the recommended operating conditions for the DDR SDRAM controller when interfacing to DDR3 SDRAM.
Note: At recommended operating conditions (see Table 3) with VDDDDR = 1.5 V.
Table 7. DDR3 SDRAM Interface DC Electrical Characteristics
Parameter/Condition
Symbol
Min
Max
Unit
Notes
I/O reference voltage
MVREF
0.49 × VDDDDR
0.51 × VDDDDR
V
2,3,4
Input high voltage
VIH
MVREF + 0.100
VDDDDR
V
5
Input low voltage
VIL
GND
MVREF – 0.100
V
5
I/O leakage current
IOZ
–50
50
μA
6
Notes: 1. VDDDDR is expected to be within 50 mV of the DRAM VDD at all times. The DRAM and memory controller can use the same or
different sources.
2. MVREF is expected to be equal to 0.5 × VDDDDR, and to track VDDDDR DC variations as measured at the receiver.
Peak-to-peak noise on MVREF may not exceed ±1% of the DC value.
3. VTT is not applied directly to the device. It is the supply to which far end signal termination is made and is expected to be
equal to MVREF with a minimum value of MVREF – 0.4 and a maximum value of MVREF + 0.04 V. VTT should track variations
in the DC-level of MVREF.
4. The voltage regulator for MVREF must be able to supply up to 250 μA.
5. Input capacitance load for DQ, DQS, and DQS signals are available in the IBIS models.
6. Output leakage is measured with all outputs are disabled, 0 V ≤ VOUT ≤ VDDDDR.
2.5.1.3 DDR2/DDR3 SDRAM Capacitance
Table 8 provides the DDR controller interface capacitance for DDR2 and DDR3 memory.
Note: At recommended operating conditions (see Table 3) with VDDDDR = 1.8 V for DDR2 memory or VDDDDR = 1.5 V for
DDR3 memory.
Table 8. DDR2/DDR3 SDRAM Capacitance
Parameter
Symbol
Min
Max
Unit
I/O capacitance: DQ, DQS, DQS
CIO
6
8
pF
Delta I/O capacitance: DQ, DQS, DQS
CDIO
—
0.5
pF
Notes: 1. This parameter is sampled. VDDDDR = 1.8 V ± 0.1 V (for DDR2), f = 1 MHz, TA = 25°C, VOUT = VDDDDR/2,
VOUT (peak-to-peak) = 0.2 V.
2. This parameter is sampled. VDDDDR = 1.5 V ± 0.075 V (for DDR3), f = 1 MHz, TA = 25°C, VOUT = VDDDDR/2,
VOUT (peak-to-peak) = 0.175 V.
Notes
1, 2
1, 2
MSC8154E Quad-Core Digital Signal Processor with Security Data Sheet, Rev. 0
Freescale Semiconductor
27