Catalogue Memory Card Interface Data Sheet
www.microrobotics.co.uk
print switch display
Page / 4
Contact the
Manufacturer		 Where to buy
this product ?		 Request
a Quote
Micro-Robotics -
/ 4
See all the products Micro-Robotics
Text version of the page
Specification
The card uses l2C bus 1 for control of the activity LED and for detection of the card state.
A PCF8574A l2C digital l/O chip provides these functions. The chip is on l2C Bus 1 address 124 (equivalent to VM-1 digital channels 240 - 247) and the digital l/O connections are assigned as in the table below. You should not attach any other device with the same address to l2C bus 1.
Chan 240 Bit 0 Card removed = H(1)
Chan 241 Bit 1 Card write protected = H (1)
Chan 242 Bit 2 Clear card removed latch : Pulse L (0)
Chan 243 Bit 3 Power control: L (0) = power on (controls 3.3V regulator that powers memory card)
Chan 244 Bit 4 "Busy" LED :L(0) = LED on
The "card removed" state is set when a memory card is not present and remains set even if a card is then inserted, until the latch is cleared by software command.
The interface to the memory card itself uses SPI mode. There are two possible groups of VM-1 ports that can be used for the SPI connection:
• Software driven SPI using channels 7, 21, 22 and 23
• Serial port 2, using channels 25, 26, 27, 28 (faster but uses serial port 2)
Ribbon Cable Connection
VM-1 Application Board
Memory Card Interface
Pin
Chan
Pin
Description
19
Vcc
1
Vcc
20
GND
2
GND
21
21
3
SPI Din = MMC Dout
22
7
4
SPI Dout = MMC Din
23
22
5
SPI CLK= MMC CLK
24
-
6
-
25
23
7
MMC/SD CS
26
9
8
I2C bus 1 SDA
27
-
9
-
28
10
10
I2C bus 1 SCL
29
25
11
SER2 HSin = CS
30
-
12
-
31
26
13
SER2 HSout = CLK
32
-
14
-
33
27
15
SER2 RXD = MMC Dout
34
-
16
-
35
28
17
SER2 TXD = MMC Din
36
-
18
-
37
Vcc
19
VCC
38
GND
20
GND
Power
The current consumption of the memory card interface itself is less than lOmAfrom the 5V line. The memory card uses 3.3V power regulated on board from the 5V supply.
Memory cards typically consume around 5OmA when in operation - consult manufacturer's data for details. This figure is added to the 5V current consumption of the assembly.
D025 V20070912
5815 Memory Card Interface
Page 3 of 4
DirectIndustry's Virtual Technical Library: PDF Catalogue | Technical Documentation | Brochure | Manual | Industrial directory | Specifications | Characteristics
Search Go
page 1 p.1
page 2 p.2
page 3 p.3
page 4 p.4
pdf-page pdf di En 2008-11-47-23