PM5381-BI PMC-Sierra, Inc., PM5381-BI Datasheet - Page 419

• Manufacturer Part Number: PM5381-BI
• Description: ATM UNI, Single Channel ATM PHY Interface for 2488.32Mbps
• Manufacturer: PMC-Sierra, Inc.

Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2000489, Issue 4
Register 0783H: RXPHY Indirect Burst Size
The RXPHY Indirect Burst Size register is an indirect address and data register. The register is
used only in POS-PHY mode of operation. See section 13.8: RXSDQ and TXSDQ Data Available
and Burst-Size Operation for more information on configuring the TXSDQ, RXSDQ, TXPHY,
and RXPHY.
BURST_SIZE[3:0]
PHY_ADDR[5:0]
Bit
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
The BURST_SIZE data register is provided to program the allowable burst size for the PHY.
The size of a burst is BURST_SIZE + 1. For example, a BURST_SIZE[3:0] = “0000”
indicates a burst size of one block. A block is equal to 16 bytes and takes 4 clocks to transfer.
The 4 bits of BURST_SIZE allow the maximum burst to be 16 blocks (256 bytes), per PHY.
.BURST_SIZE[3:0] must be set to a value less than or equal to the RXSDQ DT[7:0] value in
Register 076AH.
This register is generally used only in POS-PHY L3 mode. However, for ATM cell transfers ,
it is recommended that BURST_SIZE be set to a multiple of 4 blocks to avoid cell
fragmentation.
The PHY_ADDR bits are an indirect address that is used with BURST_SIZE data. The two
allow indirect address reads and writes using a small amount of external address space. The
PHY_ADDR is used with CONFIG_RWB and BUSY to command reads and writes. For the
S/UNI-2488, PHY_ADDR[5:0] must be set to zero.
Type
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
BUSY
CONFIG_RWB
PHY_ADDR[5]
PHY_ADDR[4]
PHY_ADDR[3]
PHY_ADDR[2]
PHY_ADDR[1]
PHY_ADDR[0]
BURST_SIZE[3]
BURST_SIZE[2]
BURST_SIZE[1]
BURST_SIZE[0]
Function
Unused
Unused
Unused
Unused
S/UNI-2488 Telecom Standard Product Datasheet
Default
X
0
0
0
0
0
0
0
X
X
X
X
0
0
1
1
Released
419