![](http://datasheet.mmic.net.cn/330000/PM73121_datasheet_16444365/PM73121_58.png)
PM73121AAL1gator II
PMC-Sierra, Inc.
L
PMC-980620
,VVXH
AAL1 SAR Processor
Data Sheet
35235,(7$5<$1'&21),'(17,$/7230&6,(55$,1&$1')25,76&86720(56,17(51$/86(
Figure 24 shows an example of the payload generation process.
3.4
The TUTOPIA block (shown in
Figure 10 on page 24
) conveys the cells emitted by the TALP to
the UTOPIA interface. Depending on the value of PHY_ENABLE input pin (refer to
“PHY_
ENABLE” on page 81
), the UTOPIA interface will either act as an ATM side (controls the write
enable signal) or as a PHY side (controls the cell available signal). As a PHY-side device, the
TUTOPIA block can also act as an SPHY device or a MPHY device (refer to
Appendix B, “Ref-
erences”, on page 203
for the UTOPIA Level 2 specification version), depending on the value of
the SPHY_EN bit in COMP_LIN_REG. The SPHY_EN bit will default to off, so if the UTOPIA
interface is being used in an MPHY environment, there will be no contention while the device is
in software reset.
Transmit UTOPIA Interface Block (TUTOPIA)
In ATM mode, the TUTOPIA block sources TATM_DATA(7:0), TATM_SOC, and /TATM_EN
while receiving /TATM_FULL. The Start-Of-Cell (SOC) indication is generated coincident with
the first byte of each cell that is transmitted on TATM_DATA. TATM_DATA and TATM_SOC
are driven at all times. The write enable signal indicates which clock cycles contain valid data for
the UTOPIA bus. The device will not assert the /TATM_EN signal until it has a full cell to send.
Figure 24.
Payload Generation
127
0
. . . .
. . . .5
6
7
8
9
10
RL_SER
TFTC writes the bytes in
pairs into T_DATA_BUFFER
Frames
0
31
Channel
7
TALP builds (segments) cell
from T_DATA_BUFFER. In
this case from DS0s 6 and 7.
T_DATA_BUFFER
6