SIMM-Sys CPU card scAT91

Description

This CPU card member of the SIMM-Sys family is built around the ATMEL AT91R40807 microcontroller. That's a highly integrated device with a 40MHz ARM7TDMI 32-bit RISC CPU core, 136kBytes of on-chip SRAM and a complete set of peripherials. The 32-bit internal architecture provides high performance while the high integration keeps cost low. The exceptional low power-consumption of the ARM processor architecture makes this device an ideal solution for not so demanding control operations. The core can be programmed using the GNU C/C++ tool-chain. There are also several other commercial development tools available from many vendors.

The card supports both 8 and 16-bit bus operations with programmable speed. It is a simple and cheep entry-level solution. It is code-compatible with the more powerful Maverick cards and with the planned StrongARM based card. The card supports up-to 8MB of FLASH memory but has no external RAM options. However the internal 136kBytes of zero-wait-state 32-bit SRAM is enough for even large control programs. When using the THUMB instruction-set program memory requirement is reduced by about 30%. This type of code can even be executed from the external 16-bit FLASH quite effectively further reducing RAM requirements.

Specification

scAT91
Clock speed	40	MHz
CPU speed	40	MHz
SRAM memory	136	kByte
FLASH memory	256-8192	kByte
Power supply	3.3	V

SIMM-Sys bus pin-out

Pin No.	Dir	Name	Description
1	O	RD	Active low read select signal.
2	O	UWE	Active low write select signal. Upper byte.
3	O	LWE	Active low write select signal. Lower byte.
4	I	RESET	Active low reset signal.
5	O	SEL0	Active low peripherial select signal.
6	O	SEL1	Active low peripherial select signal.
7	O	SEL2	Active low peripherial select signal.
8	I	IRQ0	Active low interrupt signal. Can be edge or level sensitive.
9	I	IRQ1	Active low interrupt signal. Can be edge or level sensitive.
10	I	IRQ2	Active low interrupt signal. Can be edge or level sensitive.
11	O	A0	Address lines
12	O	A1
13	O	A2
14	O	A3
15	O	A4
16	O	A5
17	O	A6
18	O	A7
19	O	A8
20	O	A9
21	I/O	D0	Data lines
22	I/O	D1
23	I/O	D2
24	I/O	D3
25	I/O	D4
26	I/O	D5
27	I/O	D6
28	I/O	D7
29	I/O	D8
30	I/O	D9
31	I/O	D10
32	I/O	D11
33	I/O	D12
34	I/O	D13
35	I/O	D14
36	I/O	D15
key
37	PWR	WAIT	Active low signal to introduce wait-states in the access cycles. Must be driven. with an open-collector driver. The pull-up resistor is provided on the CPU card.
38	PWR	GND	Ground
39	PWR	GND	Ground
40	PWR	VCC_3	3.3V nominal power supply.
41	PWR	VCC_3	3.3V nominal power supply.
42	PWR	VCC_2_5	2.5V nominal power for core supply. (not used on this card)
43	PWR	VCC_1_8	1.8V nominal power for core supply. (not used on this card)
44	I	PROG	Active low programming signal.
45	I/O	SCK0	Bit-clock for serial port 0
46		N.C.	No connection
47	I	RxD0	Read data for serial port 0
48	I/O	SCK0	bit-clock for serial port 0
49		N.C.	No connection
50	O	TxD0	Transmit data for serial port 1
51	I/O	SCK1	Read bit-clock for serial port 1
52		N.C.	No connection
53	I	RxD1	Read data for serial port 1
54	I/O	SCK1	Transmit bit-clock for serial port 1
55		N.C.	No connection
56	O	TxD1	Transmit data for serial port 1
57	I	TCLK0	Timer 0 clock input
58	I/O	TIOA0	Timer 0 IO A
59	I/O	TIOB0	Timer 0 IO B
60	I	TCLK1	Timer 1 clock input
61	I/O	TIOA1	Timer 1 IO A
62	I/O	TIOB1	Timer 1 IO B
63	I/O	P6	GPIO pin.
64	I/O	P7	GPIO pin.
65	I/O	P8	GPIO pin.
66	I/O	P9	GPIO pin.
67	I/O	P16	GPIO pin.
68	I/O	P17	GPIO pin.
69	I/O	P18	GPIO pin.
70	I/O	P19	GPIO pin.
71	O	PNPC	PnP I2C bus clock
72	I/O	PNPD	PnP I2C bus data