PM7312 pmc-sierra, PM7312 Datasheet - Page 36

• Manufacturer Part Number: PM7312
• Description: Freedm 32a1024l Assp Telecom Standard Datasheet
• Manufacturer: pmc-sierra

Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2021833, Issue 2
Pin Name
RENB
Type
Input
Pin No.
AD4
FREEDM 32A1024L ASSP Telecom Standard Product Data Sheet
Function
RXADDR[3:0].
An FREEDM 32A1024L device must not be selected for receive
data transfer unless it has been polled and responded that it has
data ready to transfer.
When the RXADDR[3:0] inputs match the device base address in
the RAPI-12 Base Address register, that FREEDM 32A1024L
device drives RPA one RXCLK cycle after sampling RXADDR[3:0].
RPA is updated on the rising edge of RXCLK.
Any-PHY Level 2 Packet Mode:
When RPA is set high, the polled FREEDM 32A1024L still has
sufficient data to undertake another Any-PHY transfer. When RPA
is set low, the polled FREEDM 32A1024L device does not have
data ready to transfer.
Any-PHY Level 3 Mode:
RPA is not used and is tri-stated.
The receive enable signal (RENB) is used to throttle the FREEDM
32A1024L.
RENB is sampled on the rising edge of RXCLK.
To commence data transfer, RENB must be sampled low.
Any-PHY Level 2 Mode:
The receive enable signal (RENB) qualifies the RXADDR[3:0]
signals for selection of a FREEDM 32A1024L device. When RENB
is sampled high and then low in consecutive RXCLK cycles, the
address on RXADDR[3:0] during the cycle when RENB is sampled
high selects a FREEDM 32A1024L device enabling it to output data
on the receive APPI. The Rx APPI of each FREEDM 32A1024L
device is identified by the device base address in the RAPI-12
Base Address register.
RENB may also be used to throttle the FREEDM 32A1024L during
data transfer on the Rx APPI. When the FREEDM 32A1024L
samples RENB high during data transfer, the FREEDM 32A1024L
will pause the data transfer and tri-state the receive APPI outputs
(except RPA) until RENB is returned low. Since the Any-PHY bus
specification does not support deselecting during data transfers,
the address on the RXADDR[3:0] inputs during the cycle before
RENB is returned low must either re-select the same FREEDM
32A1024L device or be a null address.
The polling function of the RXADDR[3:0] and RPA signals operates
regardless of the state of RENB.
It is the responsibility of the external controller to prevent overflow
by providing each FREEDM 32A1024L device on an Any-PHY
point to multi-point bus sufficient bandwidth through selection.
Any-PHY Level 3 Mode:
RENB is used to throttle the FREEDM 32A1024L during data
transfer on Rx APPI. When the FREEDM 32A1024L samples
RENB high during data transfer, the FREEDM 32A1024L will pause
the data transfer until RENB is returned low.
Released
36