Fujitsu MCM3130SS, MCP3064SS manual Signal driving conditions, Signal status, Signal driving method

7.4 Electrical Requirements

7.4.3 Signal driving conditions

(1) Signal status value

Table 7.4 shows the correspondence between the input interface signal level at the receiving end and its logic state.

	Table 7.4	Signal status
	Logic state		Signal level (at receiving end)
			Single-ended type
	True, "1", or asserted		Low (0.0 to 0.8 VDC)
	False, "0", negated,, or released		High (2.0 to 5.25 VDC)
(2) Signal driving method

Two driving methods are available: "OR-tied" type and "non-OR-tied" type as indicated in Table 7.5.

Table 7.5 Signal driving method

Signal status			Driving method
		"OR-tied" type		"Non-OR-tied" type
False (*1)	No SCSI device drives a signal.		The	A particular SCSI device drives the
	signal becomes false when the			signal false. Otherwise, no SCSI
	terminating resistor circuit is biased.			device drives the signal.
True		An SCSI device drives the signal true.
	*1	In this manual, the signal is said to be false if one of the following
		conditions is satisfied.

–The signal is actually driven by an SCSI device to become false (non-OR- tied type).

–No SCSI device is driving the signal (OR-tied type or non-OR-tied type).

In the interface operating sequence, the driving method of the BSY and RST signals which may be driven by two or more SCSI devices simultaneously must be the "OR-tied" type. Signals other than BSY, RST, or DBP are not driven by more than one SCSI device. Signals other than BSY or RST can be driven by either the "OR-tied" type or "non-OR-tied" type. The DBP signal must not be driven false in the ARBITRATION phase. For signals other than BSY or RST, both "OR-tied" and "non-OR-tied" types can be mixed on the SCSI bus.

C156-E228-02EN 7-13