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SN74SSTE32882

SCAS840 – NOVEMBER 2006

TERMINAL FUNCTIONS (continued)

TERMINAL NAME

DESCRIPTION

ELECTRICAL TYPE

Chip-select gated D-inputs. Data inputs – Clocked in on the crossing of the rising

D0–D21

edge of CK and the falling edge of CK. Re-driven only when either DCS0 or DCS1

SSTL_15 inputs

is low.

Chip select inputs – These pins initiate DRAM address/command decodes, and as

such at least one will be low when a valid address/command is present. The

DCS0, DCS1

register can be programmed to redrive all D-inputs only when at least one chip

SSTL_15 inputs

select input is low. If DCS0 and DCS1 inputs are high, D-inputs will be ignored with

the Q outputs being floating or help at previous state.

Ungated inputs – The corresponding outputs of these register bit inputs will not be

DOTD0, DODT1

SSTL_15 inputs

suspended by the DCS0 and DCS1 control unless a CMR access occurs.

Ungated inputs – The corresponding outputs of these register bit inputs will not be

DCKE0, DCKE1

SSTL_15 inputs

suspended by the DCS0 and DCS1 control unless a CMR access occurs.

PAR_IN

Parity input – Arrives one clock cycle after the corresponding data input.

SSTL_15 inputs

YB0, YA0, YB1, YA1

Positive clock outputs

1.5 V CMOS output

YB0, YA0, YB1, YA1

Complementary clock outputs

1.5 V CMOS output

Positive feedback clock output

1.5 V CMOS output

FBOUT

Complementary feedback clock output

1.5 V CMOS output

Q0A–Q21A,

Data outputs corresponding to inputs D0 .. D21

1.5 V CMOS output

Q0B–Q21B

QCS0A, QCS0B,

Data outputs corresponding to inputs DCS0 and DCS1

1.5 V CMOS output

QCS1A, QCS1B

QOTD0A, QODT0B,

Data outputs corresponding to inputs DODT0 and DODT1

1.5 V CMOS output

QOTD1A, QODT1B

QCKE0A, QCKE0B,

Data outputs corresponding to inputs DCKE0 and DCKE1

1.5 V CMOS output

QCKE1A, QCKE1B

Output error – Generated three clock cycles after the corresponding data is

QERR

Open-drain output

registered.

3

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