PM73121ꢀAAL1gator II
Data Sheet
PMC-Sierra, Inc.
PMC-980620
,VVXHꢀꢁ
AAL1 SAR Processor
The TUTOPIA responds to the /TATM_FULL signal. If the signal is not asserted, and the TUTO-
PIA has data to send, it will do so by asserting /TATM_EN. If /TATM_FULL is asserted, then the
data flow will be paused in exactly two clock cycles, until the /TATM_FULL signal allows the
cell to be completed. See the timing diagram in Figure 25 on page 42.
TATM_CLK(i)
/TATM_FULL(i)
/TATM_EN(o)
TATM_SOC(o)
TATM_DATA(o)
53
01
02
03
04
05
06
07
Figure 25. Transmit UTOPIA Timing (ATM Mode)
In PHY mode, the TUTOPIA block sources RPHY_DATA(7:0), RPHY_SOC, and RPHY_
CLAV, while receiving /RPHY_EN. The SOC indication is generated coincident with the first
byte of each cell that is transmitted on RPHY_DATA. In PHY mode, the RATM_DATA and
RATM_SOC signals are driven only when valid data is being sent; otherwise they are tristated.
/RPHY_ADDR is an input and is used only in MPHY mode.
The cell available (RPHY_CLAV) signal indicates when the device has a complete cell to send.
In SPHY mode, RPHY_CLAV is always driven. If in MPHY mode, the output enable for this sig-
nal is the /RPHY_ADDR input delayed by one cycle. In MPHY mode, /RPHY_ADDR is tied to
one of the address signals so RPHY_CLAV is driven only when polled.
The UTOPIA standard defines a 5-bit address. Since the AAL1gator II has only a single active
low address bit, multiple AAL1gator II devices can be connected in parallel to the same MPHY
interface by connecting each one to a separate address bit. In this manner, five AAL1gator IIs can
be connected to an MPHY interface using the following addresses: “0Fh”, “17h”, “1Bh”, “1Dh”,
and “1Eh” with no additional logic. If other addresses are needed or additional devices are to be
connected to the same interface, additional logic may be required.
If a cell is being read in SPHY mode, or is being read from a channel that is being polled in
MPHY mode, the value of RPHY_CLAV will be 1 until the cell has been read out of the FIFO
and there are no more cells to send. In PHY mode, the TUTOPIA block is dependent on the ATM
device to read the data by asserting the /RPHY_EN input. In SPHY mode, data is placed on
RPHY_DATA any cycle following one in which /RPHY_EN was asserted. In MPHY mode, in
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PMC [ PMC-SIERRA, INC ]
