Appendix A. RabbitCore RCM2100 Specifications

Appendix A provides the specifications for the RCM2100, and describes the conformal coating.

A.1 Electrical and Mechanical Characteristics

Figure A-1 shows the mechanical dimensions for the RCM2100.

Figure A-1. RCM2100 Dimensions

Table A-1 provides the pin 1 locations for the RCM2100 headers viewed from the top side (as in Figure A-1).

Table A-1. RCM2100 Header Pin 1 Locations

Header	Description	Pin 1 (x,y) Coordinates (Inches)
J1	RCM2100 subsystems	(3.350, 1.731)
J2	RCM2100 subsystems	(0.975, 1.731)
J3	Unisolated Ethernet signals (RCM2110 without RJ-45 jack/transformer)	(0.224, 0.861)

It is recommended that you allow for an "exclusion zone" of 0.25" (6 mm) around the RCM2100 in all directions when the RCM2100 is incorporated into an assembly that includes other components. This "exclusion zone" that you keep free of other components and boards will allow for sufficient air flow, and will help to minimize any electrical or EMI interference between adjacent boards. An "exclusion zone" of 0.12" (3 mm) is recommended below the RCM2100 when the RCM2100 is plugged into another assembly using the shortest connectors for headers J1 and J2 on the RCM2100. Figure A-2 shows this "exclusion zone."

Figure A-2. RCM2100 "Exclusion Zone"

Table A-2 lists the electrical, mechanical, and environmental specifications for the RCM2100.

Table A-2. RCM2100 Specifications 

Parameter	Specification
Board Size	2.00" × 3.50" × 0.80" (51 mm × 89 mm × 20 mm)
Operating Temperature	-40°C to +70°C
Humidity	5% to 95%, noncondensing
Input Voltage	4.75 V to 5.25 V DC
Current	140 mA at 22.1 MHz, 5 V DC; 82 mA at 11.05 MHz, 5 V DC
General-Purpose I/O	34 parallel I/0 lines grouped in five 8-bit ports (shared with serial ports): 20 configurable for I/O, 8 fixed inputs, 6 fixed outputs
Memory, I/O Interface	13 address lines, 8 data lines, I/O read/write, buffer enable
Additional Digital Inputs	Startup mode (2 for master/slave), reset in
Additional Digital Outputs	Status, clock, watchdog out, reset out
Ethernet Interface	10base-T
Microprocessor	Rabbit 2000
Clock	22.1 MHz
SRAM	512K × 8, surface mount
Flash Memory	Two 256K × 8, surface mount
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 690,625 bps maximum synchronous 5.52 Mbps
Slave Interface	A slave port allows the RabbitCore RCM2100 to be used as an intelligent peripheral device slaved to a master processor, which may either be another Rabbit 2000 or any other type of processor
Watchdog/Supervisor	Yes
Time/Date Clock	Yes
Socket Strip (for connection to headers J1 and J2)	Pinrex 2x20, 2 mm pitch (PS2S-2X20GOB)
Backup Battery	Provision for user-supplied backup battery (2.85 V to 3.15 V) via connections on header J2

A.1.1 Headers

The RCM2100 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-3 shows the layout of another board for the RCM2100 to be plugged in to. These values are relative to the header connectors.

Hole diameters of 0.035 inches are recommended for the user board that the RabbitCore RCM2100 will be plugged into.

Figure A-3. User Board Footprint for the RCM2100

A.1.2 Physical Mounting

A 9/32" (7 mm) standoff with a 4-40 screw is recommended to attach the RCM2100 to a user board at the hole position shown in Figure A-3. A standoff with a screw may also be used at the hole position close to the RJ-45 Ethernet connector for a second anchor, or you may opt to have a nut and bolt with a wire at this hole position if you removed resistor R5 and elected to ground the RJ-45 Ethernet connector to the chassis.

A.2 Bus Loading

You must pay careful attention to bus loading when designing an interface to the RabbitCore RCM2100. This section provides bus loading information for external devices.

Table A-3 lists the capacitance for the various RCM2100 I/O ports.

Table A-3. Capacitance of RCM2100 I/O Ports

I/O Ports	Input Capacitance		Output Capacitance
	Typ.	Max.	Typ.	Max.
Parallel Ports A to E	6 pF	12 pF	10 pF	14 pF
Data Lines BD0-BD7	12 pF	18 pF	18 pF	22 pF
Address Lines BA0-BA12	--	--	8 pF	12 pF

Table A-4 lists the external capacitive bus loading for the various RCM2100 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 +70°C

Output Port	Clock Speed (MHz)	Maximum External Capacitive Loading (pF)
A[12:0] D[7:0]	22.1	50
PD[3:0]	22.1	100
PA[7:0] PB[7,6] PC[6,4,2,0] PD[7:4]1 PE[7:0]	22.1	90
All data, address, and I/O lines with clock doubler disabled	11.0592	100

1 The Parallel Port D outputs (PD[7:4]) are available only on the RCM2120 and the RCM2130 models.

Figure A-4 shows a typical timing diagram for the Rabbit 2000 microprocessor memory read and write cycles.

Figure A-4. 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. Tsetup is the data setup time relative to the clock. Tsetup is specified from 30%/70% of the VDD voltage level.

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 22.1 MHz CPU clock and capacitive loading on address and data lines of less than 100 pF per pin. Pins A0-A12 and D0-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 RCM2100.

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	25/25
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.

A.5 Conformal Coating

The areas around the crystal oscillator has had the Dow Corning silicone-based 1-2620 conformal coating applied. The conformally coated area is shown in Figure A-5. The conformal coating protects these high-impedance circuits from the effects of moisture and contaminants over time.

Figure A-5. RCM2100 Areas Receiving Conformal Coating

Any components in the conformally coated area may be replaced using standard soldering procedures for surface-mounted components. A new conformal coating should then be applied to offer continuing protection against the effects of moisture and contaminants.

NOTE	For more information on conformal coatings, refer to Rabbit Semiconductor Technical Note 303, Conformal Coatings.