Appendix A. Specifications

Appendix A provides the specifications for the RCM2000, and describes the conformal coating.

A.1 Electrical and Mechanical Specifications

Figure A-1 shows the mechanical dimensions for the RCM2000.

Figure A-1. RCM2000 Dimensions

Table A-1 provides the pin 1 locations for the RCM2000 headers viewed from the top side (as in Figure A-1).

Table A-1. RCM2000 Header Pin 1 Locations

Header	Description	Pin 1 (x,y) Coordinates (Inches)
J1	RCM2000 subsystems	(0.221, 1.675)
J2	RCM2000 subsystems	(2.181, 1.675)
J3	Programming port	(1.600, 0.214)

Table A-2 lists the electrical, mechanical, and environmental specifications for the RCM2000.

Table A-2. RCM2000 Specifications 

Parameter	Specification
Board Size	1.90" × 2.30" × 0.50" (48.3 mm × 58.4 mm × 12.7 mm)
Operating Temperature	-40°C to +85°C
Storage Temperature	-55°C to +125°C
Humidity	5% to 95%, noncondensing
Input Voltage	4.75 V to 5.25 V DC
Current	54 mA at 9.216 MHz, 5 V DC 70 mA at 12.9024 MHz, 5 V DC 88 mA at 18.432 MHz, 5 V DC 120 mA at 25.8048 MHz, 5 V DC
Standby Current	10 µA (typical)
General-Purpose I/O	40 parallel I/0 lines grouped in five 8-bit ports: 24 bidirectional, 10 inputs only, 6 outputs only
Memory, I/O Interface	13 address lines, 8 data lines, I/O read/write, buffer enable, status, clock
Additional Digital Inputs	2 startup mode (for master/slave), reset in
Additional Digital Outputs	Watchdog output, reset out
Microprocessor	Rabbit 2000
Clock	25.8048 MHz (18.432 MHz option)
SRAM	512K (supports 32K-512K)
Flash EPROM	256K (supports 128K-512K)
Timers	Five 8-bit timers cascadable in pairs, one 10-bit timer with 2 match registers that each have an interrupt
Serial Ports	Four CMOS-compatible ports. Two ports are configurable as clocked ports, one is configurable as RS-232 programming port.
Serial Rate	CMOS maximum asynchronous 806,400 bps maximum synchronous 6.45 Mbps
Watchdog/Supervisor	Yes
Time/Date Clock	Yes
Socket Strip (for connection to headers J1 and J2)	Pinrex 2x20, 2 mm pitch (PS2S-2X20GOB)
Recommended Standoff (to attach RabbitCore 2000 to user board)	9/32" (7.14) with 4-40 screw
Backup Battery	Provision for user-supplied backup battery (2.8 V to 3.3 V) via connections on header J2

A.1.1 Headers

The RCM2000 uses headers at J1, J2, and J3 for physical connection to other boards. J1 and J2 are 2 ×  20 SMT headers with a 2 mm pin spacing. J3 is a 2 ×  5 header with a 2 mm pin spacing.

Figure A-2 shows the layout of another board for the RCM2000 to be plugged in to. These values are relative to the header connectors.

Figure A-2. J1 and J2 Header Layout (Top View)

NOTE	Two holes were added near the top of the RCM2000 above headers J1 and J2 starting with RCM2000 versions marked 175-0201 on the bottom side. These holes facilitate factory testing and must not be used for mounting or attaching other hardware.

A.2 Bus Loading

You must pay careful attention to bus loading when designing an interface to the RCM2000. This section provides bus loading for external devices.

Table A-3 lists the capacitance for the various RCM2000 I/O ports.

Table A-3. Capacitance of RCM2000 I/O Ports

I/O Ports	Input Capacitance (pF)		Output Capacitance (pF)
	Typ.	Max.	Typ.	Max.
Parallel Ports A to E	6 pF	12 pF	10 pF	14 pF
Data Lines D0-D7	16 pF	30 pF	24 pF	32 pF
Address Lines A0-A12	--	--	24 pF	32 pF

Table A-4 lists the external capacitive bus loading for the various Rabbit 2000 output ports. Be sure to add the loads for the devices you are using in your custom system and verify that they do not exceed the values in Table A-4.

Table A-4. External Capacitive Bus Loading -40°C to +85°C

Output Port	Clock Speed (MHz)	Maximum External Capacitive Loading (pF)
A[12:1] D[7:1]	25.8	50
A[12:1] D[7:1]	18.4	55 for 90 ns flash 100 for 55 ns flash1
A0 D0	25.8, 18.4	100
PD[3:0]	25.8, 18.4,	100
PA[7:0] PB[7,6] PC[6,4,2,0] PD[7:4] PE[7:0]	25.8, 18.4	90
All data, address, and I/O lines with clock doubler disabled	12.9, 9.2	100

1 The RCM2020 operating at 18.4 MHz will typically come with a flash EPROM whose access time is 55 ns. Because of the volatility of the memory market, a 90 ns flash EPROM could be used on the RCM2020.

The values from the table above are derived using 55 ns (25.8 MHz version) and 90 ns (18.4 MHz version) memory access times. External capacitive loading can be improved by 10 pF for commercial temperature ranges, but do not exceed 100 pF. See the AC timing specifications in the Rabbit 2000 Microprocessor User's Manual for more information.

Figure A-3 shows a typical timing diagram for the Rabbit 2000 microprocessor memory read and write cycles.

Figure A-3. Memory Read and Write Cycles

Tadr is the time required for the address output to reach 0.8 V. This time depends on the bus loading. A0 has a stronger driver and can handle larger capacitive loads than the other address lines. Tsetup is the data setup time relative to the clock. Tsetup is specified from 30%/70% of the VDD voltage level. Add 1.5 ns to Tadr for each 10 pF of additional bus loading above 70 pF.

A.3 Rabbit 2000 DC Characteristics

Table A-5 outlines the DC characteristics for the Rabbit 2000 at 5.0 V over the recommended operating temperature range from Ta = -40°C to +85°C, VDD = 4.5 V to 5.5 V.

Table A-5. 5.0 Volt DC Characteristics

Symbol	Parameter	Test Conditions	Min	Typ	Max	Units
IIH	Input Leakage High	VIN = VDD, VDD = 5.5 V			10	µA
IIL	Input Leakage Low (no pull-up)	VIN = VSS, VDD = 5.5 V	-10			µA
IOZ	Output Leakage (no pull-up)	VIN = VDD or VSS, VDD = 5.5 V	-10		10	µA
VIL	CMOS Input Low Voltage				0.3 x VDD	V
VIH	CMOS Input High Voltage		0.7 x VDD			V
VT	CMOS Switching Threshold	VDD = 5.0 V, 25°C		2.4		V
VOL	CMOS Output Low Voltage	IOL = See Table A-6 (sinking) VDD = 4.5 V		0.2	0.4	V
VOH	CMOS Output High Voltage	IOH = See Table A-6 (sourcing) VDD = 4.5 V	0.7 x VDD	4.2		V

A.4 I/O Buffer Sourcing and Sinking Limit

Unless otherwise specified, the Rabbit I/O buffers are capable of sourcing and sinking 8 mA of current per pin at full AC switching speed. Full AC switching assumes a 25.8 MHz CPU clock and capacitive loading on address and data lines of less than 100 pF per pin. Address pin A0 and data pin D0 are rated at 16 mA each. Pins A1-A12 and D1-D7 are each rated at 8 mA. The absolute maximum operating voltage on all I/O is VDD + 0.5 V, or 5.5 V.

Table A-6 shows the AC and DC output drive limits of the parallel I/O buffers when the Rabbit 2000 is used in the RabbitCore 2000.

Table A-6. I/O Buffer Sourcing and Sinking Capability

Pin Name	Output Drive Sourcing1/Sinking2 Limits (mA)
Output Port Name	Full AC Switching SRC/SNK	Maximum3 DC Output Drive SRC/SNK
PA [7:0]	8/8	12/12
PB [7, 1, 0]	8/8	12/12
PC [6, 4, 2, 0]	8/8	12/12
PD [7:4]	8/8	12/12
PD [3:0]4	16/16	12/25
PE [7:0]	8/8	12/12

1 The maximum DC sourcing current for I/O buffers between VDD pins is 112 mA. 2 The maximum DC sinking current for I/O buffers between VSS pins is 150 mA. 3 The maximum DC output drive on I/O buffers must be adjusted to take into consideration the current demands made my AC switching outputs, capacitive loading on switching outputs, and switching voltage. The current drawn by all switching and nonswitching I/O must not exceed the limits specified in the first two footnotes. 4 The combined sourcing from Port D [7:0] may need to be adjusted so as not to exceed the 112 mA sourcing limit requirement specified in the first footnote.

Some of the values listed are different from those listed in the Rabbit 2000 Microprocessor User's Manual to take into account external loading of the Rabbit 2000 while it is part of the RCM2000. Loads that exceed the values listed above need to be buffered.