Texas Instruments TNETX3270 specifications Host DIO interface

TNETX3270

ThunderSWITCH 24/3 ETHERNET SWITCH

WITH 24 10-MBIT/S PORTS AND 3 10-/100-MBIT/S PORTS

SPWS043B ± NOVEMBER 1997 ± REVISED APRIL 1999

					Terminal Functions (Continued)
host DIO interface
	TERMINAL		I/O	INTERNAL							DESCRIPTION
	NAME	NO.		RESISTOR
	SAD1	143
			I	Pullup	DIO address bus. SAD1 and SAD0 select the internal host registers, when SDMA is high.
	SAD0	142
		138	I	Pullup	DIO chip select. When low,				indicates a DIO port access is valid.
	SCS						SCS
					DIO DMA select. When low,					modifies the behavior of the DIO interface to allow it to operate
						SDMA
					with an external DMA controller. The SAD0 and SAD1 terminals are not used to select the internal
					host register for the access. Instead, the DIO address to access is provided by the DMA address
					register, and one of two host register addresses is selected according to DMAinc in the Syscontrol
		123	I	Pullup	register.
	SDMA
					± If DMAinc = 1, accesses are the DIOdatainc register and DMAaddress increments after each
					access.
					± If DMAinc = 0, accesses are the DIOdata register, and DMAaddress does not increment after
					each address.
	SDATA7	136
	SDATA6	135
	SDATA5	133			DIO data interface bus (byte-wide bidirectional DIO port). SDATA7 is the most significant bit and
	SDATA4	131	I/O	Pullup
	SDATA3	130			SDATA0 is the least significant bit.
	SDATA2	129
	SDATA1	127
	SDATA0	126
	SINT	140	O	None	DIO interrupt line (interrupt to the attached microprocessor). The interrupt originating event is
					stored in the Int register.
					DIO ready signal
		139	O	Pullup	± When low during reads,			SRDY			indicates to the host when data is valid to be read.
	SRDY
					± When low during writes, SRDY indicates when data has been received after SCS is taken
					high. SRDY is driven high for one clock cycle before placing the output in high impedance.
					DIO read not write
		125	I	Pullup
	SRNW				± When high, read operation is selected.
					± When low, write operation is selected.
					Network management port, receive ready. When high, SRXRDY indicates that the network
	SRXRDY	145	O	None	management port's RX buffers are empty and the network management port is able to receive
					a frame.
					Network management port, transmit ready. STXRDY indicates that at least one frame buffer is
					available to be read by the management CPU.
	STXRDY	144	O	None	± It outputs as a 1 if any of the end-of-frame (EOF) bits, start-of-frame (SOF) bits, or one of the
					bits in NMTxcontrol is set to 1.
					± Otherwise, it outputs 0.

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