KSZ8842MQL Datasheet, PDF (68/141 Pages) Micrel Semiconductor – 2-Port Ethernet Switch with Non-PCI Interface

Micrel, Inc.
KSZ8842-16/32 MQL/MVL/MVLI/MBL
Bank 17 RX Frame Data Pointer Register (0x06): RXFDPR
The value of this register determines the address to be accessed within the RXQ frame buffer. When the Auto Increment
is set, it will automatically increment the RXQ Pointer on read accesses to the data register.
The counter is incremented is by one for every byte access, by two for every word access, and by four for every double
word access.
Bit
15
14
13-11
10-0
Default Value R/W
-
RO
0x0
RW
-
RO
0x0
RW
Description
Reserved
RXFPAI RX Frame Pointer Auto Increment
When this bit is set, the RXQ Address register increments automatically on accesses
to the data register. The increment is by one for every byte access, by two for every
word access, and by four for every double word access.
When this bit is reset, the RX frame data pointer is manually controlled by user to
access the RX frame location.
Reserved
RXFP RX Frame Pointer
RX Frame data pointer index to the Data register for access.
This field reset to next available RX frame location when RX Frame release command
is issued (through the RXQ command register).
Bank 17 QMU Data Register Low (0x08): QDRL
This register QDRL(0x08-0x09) contains the Low data word presently addressed by the pointer register. Reading maps
from the RXQ, and writing maps to the TXQ.
Bit
15-0
Default Value R/W
-
RW
Description
QDRL Queue Data Register Low
This register is mapped into two uni-directional buffers for 16-bit buses, and one uni-
directional buffer for 32-bit buses, (TXQ when Write, RXQ when Read) that allow
moving words to and from the KSZ8842M regardless of whether the pointer is even,
odd, or Dword aligned. Byte, word, and Dword access can be mixed on the fly in any
order. This register along with DQRH is mapped into two consecutive word locations
for 16-bit buses, or one word location for 32-bit buses, to facilitate Dword move
operations.
Bank 17 QMU Data Register High (0x0A): QDRH
This register QDRH(0x0A-0x0B) contains the High data word presently addressed by the pointer register. Reading maps
from the RXQ, and writing maps to the TXQ.
Bit
15-0
Default Value R/W
-
RW
Description
QDRL Queue Data Register High
This register is mapped into two uni-directional buffers for 16-bit buses, and one uni-
directional buffer for 32-bit buses, (TXQ when Write, RXQ when Read) that allow
moving words to and from the KSZ8842M regardless of whether the pointer is even,
odd, or dword aligned. Byte, word, and Dword access can be mixed on the fly in any
order. This register along with DQRL is mapped into two consecutive word locations
for 16-bit buses, or one word location for 32-bit buses, to facilitate Dword move
operations.
October 2007
68
M9999-102207-1.9