CY3220LINBUS-RD Cypress Semiconductor Corp, CY3220LINBUS-RD Datasheet - Page 42

• Manufacturer Part Number: CY3220LINBUS-RD
• Description: KIT REF DESIGN LIN BUS
• Manufacturer: Cypress Semiconductor Corp
• Series: PSoC®r

Specifications of CY3220LINBUS-RD

• Main Purpose: Interface, LIN
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: CY8C27143, CY8C27443
• Processor To Be Evaluated: CY8C27143-24PXI and CY8C27443-24PXI
• Interface Type: RS-232
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant
• Other names: 428-1926

4. Slave Design IP
l_signal_handle: Name of the frame to which bytes have to
be written.
start: The offset from where the bytes have to be written.
count: Number of counts to be written.
data: Buffer from which the data have to be copied.
Example: For example, to write two bytes to Frame1 from
the first byte of the buffer from another buffer called Temp-
Buffer, use this code:
l_bytes_wr(Frame1, 0, 2, TempBuffer);
Note that the first byte of the frame buffer has an offset of
zero. That is why zero was used as the offset parameter.
Returns: None.
l_ifc_read_status
C Prototype: l_u16 l_ifc_read_status(void);
Description: The call returns a 16-bit status word.
Parameters: None.
Returns: 16-bit status word.
Table 4-3.
Usage Notes: This function is used by the foreground pro-
gram to monitor the LIN bus for error conditions. It is also
used by the main program to check if the slave has to be put
into power-down mode by checking the go to sleep bit. For
example, use this code to trap any errors in the LIN bus:
if((char)l_ifc_read_status() &
bfSTATUS_ERROR_IN_RESPONSE)
{
}
l_ifc_irq_disable
C Prototype: void l_ifc_irq_disable(void);
Description: Disables system interrupts.
Parameters: None.
40
Bit 0
Bit 1
Bit 2
Bit 3
Bits 4 to7
Bits 8 to 15
Number
Bit
Error in Response: This bit is set whenever there is an error
in the LIN transaction.
Successful Transfer: This bit is set when the last frame was
successfully processed.
Overrun: This bit is set when the last status was not read
before the next update.
Go To Sleep: This bit is set when a go to sleep command
has been received. This bit is also set by the firmware when
a bus idle is detected.
Last Frame Protected ID: This byte has the protected ID of
the frame that was processed last.
// Code to process error
Description
Cypress Semiconductor – Rev. **
Returns: None.
l_ifc_irq_restore
C Prototype: void l_ifc_irq_restore(void);
Description: Restores system interrupts.
Parameters: None.
Returns: None.
l_ifc_wake_up
C Prototype: void l_ifc_wake_up(void);
Description: Generates a wakeup command on the bus.
This function sends a 0xF0 on the Lin bus, which will simu-
late a wakeup call.
Parameters: None.
Returns: None.
4.8
4.8.1
The following tables list the time taken by some of the impor-
tant branches of ISRs in the LIN slave node IP. The CPU
overload for various conditions is roughly computed using
these tables.
Note that the times indicated are approximate and may
change during future revisions of the firmware
Table 4-4. GPIO Interrupt
Table 4-5. Rx Interrupt
1
2
3
4
5
6
7
8
1
2
3
4
5
Sl. No.
Sl. No.
Dominant Break
Recessive Break
Synchro Field Start
Falling Edge 1
Falling Edge 2
Falling Edge 3
Falling Edge 4
Total Time for Break/Synch
Known ID received, TX initialized
Unknown ID received
Known ID received, RX initialized 390
Frame reception complete
One data byte received
Time Study
ISR and Function Timing
Stage
Stage
LIN Bus 2.0 Reference Design
264
325
224
351
296
296
3618
940
1103
1747
159
No. Of Cycles
No. Of Cycles
October 25, 2006
.
11.00
13.54
9.33
14.63
12.33
12.33
150.75
223.92
45.96
72.79
6.63
Time(
39.17
16.25
Time(
µ
µ
S)
S)