Intel 80960HT, 80960HD, 80960HA manual Hx Processor Family Pin Descriptions Sheet 4, Clkin

80960HA/HD/HT

Table 7. 80960Hx Processor Family Pin Descriptions (Sheet 4 of 4)

		Name			Type	Description
						CLOCK INPUT provides the time base for the 80960Hx. All internal circuitry is
						synchronized to CLKIN. All input and output timings are specified relative to
	CLKIN				I	CLKIN.
						For the 80960HD, the 2x internal clock is derived by multiplying the CLKIN
						frequency by two. For the 80960HT, the 3x internal clock is derived by multiplying
						the CLKIN frequency by three.
					I	RESET forces the device into reset.	RESET	causes all external and internal
	RESET
						signals to return to their reset state (when defined). The rising edge of RESET
					A(L)
						starts the processor boot sequence.
					I	SELF TEST, when asserted during the rising edge of				causes the
	STEST								RESET,
					S(L)	processor to execute its built in self-test.
					O	FAIL indicates a failure of the processor’s built-in self-test performed during
						initialization. FAIL is asserted immediately out of reset and toggles during self-test
					H(Q)
				FAIL		to indicate the status of individual tests. When self-test passes, FAIL is de-
					B(Q)
						asserted and the processor branches to the user’s initialization code. When self-
					R(0)
						test fails, the FAIL pin asserts and the processor ceases execution.
						ON-CIRCUIT EMULATION control: the processor samples this pin during reset.
					I	When it is asserted low at the end of reset, the processor enters ONCE mode. In
		ONCE				ONCE mode, the processor stops all clocks and floats all output pins except the
						TDO pin. ONCE uses an internal pull-up resistor; see RPU definition in Table 22,
						“80960Hx DC Characteristics” on page 40. Pull this pin high when not in use.
				TCK	I	TEST CLOCK provides the clocking function for IEEE 1149.1 Boundary Scan
						testing.
				TDI	I	TEST DATA INPUT is the serial input pin for IEEE 1149.1 Boundary Scan testing.
						TDI uses an internal pull-up resistor; see RPU definition in Table 22, “80960Hx DC
						Characteristics” on page 40.
				TDO	O	TEST DATA OUTPUT is the serial output pin for IEEE 1149.1 Boundary Scan
						testing. ONCE does not disable this pin.
						TEST RESET asynchronously resets the Test Access Port (TAP) controller.
											TRST
					I	must be held low at least 10,000 clock cycles after power-up. One method is to
			TRST			provide TRST with a separate power-on-reset circuit. TRST includes an internal
						pull-up resistor; see RPU definition in Table 22, “80960Hx DC Characteristics” on
						page 40. Pull this pin low when not in use.
						TEST MODE SELECT is sampled at the rising edge of TCK. TCK controls the
				TMS	I	sequence of TAP controller state changes for IEEE 1149.1 Boundary Scan
						testing. TMS uses an internal pull-up resistor; see RPU definition in Table 22,
						“80960Hx DC Characteristics” on page 40.
		VCC5			I	5 V REFERENCE VOLTAGE input is the reference voltage for the 5 V-tolerant I/O
						buffers. Connect this signal to +5 V for use with inputs which exceed 3.3 V. When
						all inputs are from 3.3 V components, connect this signal to 3.3 V.
VCCPLL					I	PLL VOLTAGE is the +3.3 VDC analog input for the PLL.
						VOLTAGE DETECT signal allows external system logic to distinguish between a
						5 V 80960Cx processor and the 3.3 V 80960Hx processor. This signal is active
VOLDET					O	low for a 3.3 V 80960Hx (it is high impedance for 5 V 80960Cx). This pin is
						available only on the PGA version.
						0 = 80960Hx
						1 = 80960Cx

Datasheet 19