VS1005g Datasheet
10 VS1005 PERIPHERALS AND REGISTERS
don’t care.
ETH_TXPNTR_BUSY is the ethernet transmitter busy flag. In SPI slave mode this flag is set if
transmitter is enabled and chip select line is in its active state (low).
ETH_TXPNTR_START enables the ethernet transmitter. When this register is set the transmit-
ter changes from idle to busy state and sends ETH_TXLEN[11:0] number of bytes. Before this
register is set the packet data must be stored in peripheral memory and tx address pointer and
tx packet length registers must be configured. In SPI slave mode this register is zero.
ETH_TXPNTR[10:0] is the ethernet/SPI transmitter memory address pointer. This pointer is
loaded with packet start address before transmitter is enabled.
ETH_RXLEN Bits
Name
Bits Description
ETH_RXLEN_PMODE
15 Peripheral mode select: Ethernet (0) / SPI
slave mode (1)
ETH_RXLEN_STCLK
ETH_RXLEN[11:0]
14 SPI slave transmitter clock configuration
11:0 Ethernet receiver packet size in bytes
ETH_RXLEN_PMODE register configures the peripheral to ethernet mode or to SPI slave
mode. When register is reset (default state) the peripheral is in ethernet mode.
ETH_RXLEN_STCLK selects SPI slave transmitter clock edge. When register is reset the SPI
out data is written after falling SPI clock edge. When register is set the data is written after
rise edge. With high SPI bit rates (SPI clock > core clock / 6) the rise edge should be used. It
should be noted that the SPI slave clock can not exceed core clock / 4 at any time. In ethernet
mode this register is don’t care.
ETH_RXLEN[11:0] register is loaded with ethernet/SPI receiver packet length counter when
receiver returns from busy state to idle (packet end). Packet length is given in bytes.
ETH_RXPNTR Bits
Name
Bits Description
ETH_RXPNTR_CRCOK
ETH_RXPNTR_NEWPKT
ETH_RXPNTR_BUSY
ETH_RXPNTR_ENA
ETH_RXPNTR[10:0]
15 Ethernet receiver crc status flag
14 Ethernet receiver packet received flag
13 Ethernet receiver busy
12 Ethernet receiver enable
10:0 Ethernet receiver memory address pointer
ETH_RXPNTR_CRCOK is the received packet crc status flag. Receiver sets the flag if the
received packet crc was correct. Flag must be reset by user (write ’1’). In SPI slave mode the
crc flag is set if last four bytes were 0xFF.
ETH_RXPNTR_NEWPKT is the flag for incoming packet. The receiver sets the flag when it
changes its state from busy to idle. Flag must be reset by user (write ’1’). In spi mode this
register is zero.
ETH_RXPNTR_BUSY is a busy flag for ethernet/SPI slave receiver. This receiver sets the flag
when changes its state from idle to busy state.
ETH_RXPNTR_ENA register places the ethernet receiver on hold for incoming packet when
set. When packet start is detected the receiver switches from idle to busy state. Receiver
Version: 0.2, 2012-03-16
55
ETC [ ETC ]
