Micrel, Inc.
MIC2555
USB Receive Operation
Inputs
Outputs
USB Mode
Suspend
D+
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
D-
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
DAT_VP_RX
SE0_VM_TX
RCV
n/a
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
undefined
1
0
0
0
1
0
0
0
0
0
1
1
0
0
1
1
1
n/a
0
n/a
undefined
n/a
DAT-SE0
0
1
0
1
0
1
0
1
0
1
0
1
n/a
n/a
n/a
n/a
undefined
1
0
undefined
n/a
VP-VM
n/a
n/a
n/a
If the transceiver is in the DAT-SE0 mode, and the
suspend bit has not been set, then the DAT_VP_RX
pin always follows the output of the differential receiver
during receive operation. The DAT_SE0 pin is not
gated by the outputs of the single ended receivers. In
the VP-VM mode, the RVC pin always follows the
output of the differential receiver. The RVC pin is not
gated by the outputs of the singled ended receivers.
Single-Ended Receivers
The Single Ended Receivers detect the logic levels on
the D+ and D- lines, and provide this information to the
Single Ended Decoder.
Single-Ended Decoder
Behavior of the Single-Ended Decoder is dependent
upon the power mode of the transceiver. If transceiver is
in the Suspend power mode, and dat_se0 = 1 (DAT-SE0
mode), then the DAT_VP_RX pin will reflect the output
of the D+ single ended receiver. This is necessary so
that a controller connected to the transceiver can detect
data pulsing while the transceiver is in suspended mode.
UART mode: uart_en = 1
suspend DAT_VP SE0_VM
D+
RX data
Z
D-
SE0_VM
Z
0
1
SE_DP
Z
TX data
Z
Z = Tri-State
M9999-060805
(408) 955-1690
June 2005
16
MICREL [ MICREL SEMICONDUCTOR ]
