Ampro Corporation Littleboard 550 manual Pin # Signal Descriptions J1 Row C

Chapter 3				Hardware
Table 3-7. PC/104 Interface Pin/Signal Descriptions (J1C)
	Pin #		Signal	Descriptions (J1 Row C)
	1 (C0)		GND	Ground
	2 (C1)		SBHE*	System Byte High Enable – This signal is driven low to indicate a
				transfer of data on the high half of the data bus (D15 to D8).
	3 (C2)		LA23	Lactchable Address 23 – This signal must be latched by the resource if
				the line is required for the entire data cycle.
	4 (C3)		LA22	Lactchable Address 22 – Refer to LA23, pin-C2, for more information.
	5 (C4)		LA21	Lactchable Address 21 – Refer to LA23, pin-C2, for more information.
	6 (C5)		LA20	Lactchable Address 20 – Refer to LA23, pin-C2, for more information.
	7 (C6)		LA19	Lactchable Address 19 – Refer to LA23, pin-C2, for more information.
	8 (C7)		LA18	Lactchable Address 18 – Refer to LA23, pin-C2, for more information.
	9 (C8)		LA17	Lactchable Address 17 – Refer to LA23, pin-C2, for more information.
	10	(C9)	MEMR*	Memory Read – This signal instructs a selected memory device to drive
				data onto the data bus. It is active on all memory read cycles.
	11	(C10)	MEMW*	Memory Write – This signal instructs a selected memory device to store
				data currently on the data bus. It is active on all memory write cycles.
	12	(C11)	SD8	System Data 8 – Refer to SD7, pin-A2, for more information.
	13	(C12)	SD9	System Data 9 – Refer to SD7, pin-A2, for more information.
	14	(C13)	SD10	System Data 10 – Refer to SD7, pin-A2, for more information.
	15	(C14)	SD11	System Data 11 – Refer to SD7, pin-A2, for more information.
	16	(C15)	SD12	System Data 12 – Refer to SD7, pin-A2, for more information.
	17	(C16)	SD13	System Data 13 – Refer to SD7, pin-A2, for more information.
	18	(C17)	SD14	System Data 14 – Refer to SD7, pin-A2, for more information.
	19	(C18)	SD15	System Data 15 – Refer to SD7, pin-A2, for more information.
	20	(C19)	Key	Key Pin (Not connected)

Notes: The shaded area denotes power or ground. The signals marked with * = Negative true logic.

Table 3-8. PC/104 Interface Pin/Signal Descriptions (J1D)

Pin #	Signal	Descriptions (J1 Row D)
21 (D0)	GND	Ground
22 (D1)	MEMCS16*	Memory Chip Select 16 – This is signal is driven low by a memory slave
		device to indicates it is cable of performing a 16-bit memory data
		transfer. This signal is driven from a decode of the LA23 to LA17
		address lines.
23 (D2)	IOCS16*	I/O Chip Select 16 – This signal is driven low by an I/O slave device to
		indicate it is capable of performing a 16-bit I/O data transfer. This signal
		is driven from a decode of the SA15 to SA0 address lines.
24 (D3)	IRQ10	Interrupt Request 10 – Asserted by a device when it has pending interrupt
		request. Only one device may use the request line at a time.
25 (D4)	IRQ11	Interrupt Request 11 – Asserted by a device when it has pending interrupt
		request. Only one device may use the request line at a time.
26 (D5)	IRQ12	Interrupt Request 12 – Asserted by a device when it has pending interrupt
		request. Only one device may use the request line at a time.

LittleBoard 550 Reference Manual 33