HighWire HW400c/2 User Reference Guide Rev 1.0
4.2.21 SPI Read Byte Offset Register (SOR)
g
ding from
e BCM5388 Ethernet Switch SPI port. In the case where the entire register is not
Tab x1C
The SPI Byte Offset Select Register is a Read/Write register. It is used for selectin
the desired byte offset (within the register selected by the SAR) when rea
th
being read, the SOR can be set to a non-zero value to index to the desired starting
byte.
le 51. SPI Read Byte Offset Select Register (SOR) Offset Address 0
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Reserved Reserved Reserved Reserved Reserved SOR2 SOR1 SOR0
SOR[2:0] = 000 No by
= 001 Select 2 byte
= 010 Select 3rd byte
…. ….
th byte
4.2.22 Read Byt
Bit 7 Bit 5 Bit 3 Bit 2 1 Bit 0
te offset (Select 1st byte)
nd
= 111 Select 8
e Count Register (RBC)
The Read Byte Count Register is a Read/Write register. It is used for setting the
umber of bytes to be read when reading from the BCM5388 SPI port. When this n
register is written, the internal SPI Read State Machine is initiated. After all
requested bytes are read from the BCM5388, the RBC value is cleared.
Table 52. Read Byte Count Register (RBC) Offset Address 0x1D
Bit 6 Bit 4 Bit
Reserved Re ed Reserved Re d RBC3 RBC2 RBC1 RBC0 serv serve
0] = 0x1 – 0x8 ead from one to ei 5388
RBC[3: R ght bytes from the BCM
October 10, 2006 Copyright 2006, SBE, Inc. Page 59