ISO7816 Smart Card mode on TM4C129

Hello Hiroyasu

The Baud Rate sets the TX Clock

Regards
Amit

Hi, Amit

Thank you for your reply.
If TX clock is 3571200(= 9600*372),RX Baud rate will 3571200.
ISO7816 should be difference TX clock and RX baud rate.

Do you know how to set for difference clock?

Best Regards
Hiroyasu

Hello Hiroyasu

I do not think there is a method to have different RX and TX clock. The TX line is the clock and the RX line is used for data communication in half duplex mode.

Regards
Amit

Hi, Amit

ISO7816 says like this.

ISO7816 3.1.a - Answer to Reset in asynchronous transmission

* Bit duration
""""""""""""
The nominal bit duration used on I/O is defined as one Elementary Time Unit (etu).
For cards having internal clock, the initial etu is 1/9600 s.
For cards using the external clock, there is a linear relationship between the Elementary Time Unit used on I/O and the period provided by the interface device on CLK.
The initial etu is 372/fi s where fi is in Hertz.
The initial frequency fi is provided by the interface device on CLK during the Answer to Reset.
In order to read the initial character (TS), all cards shall initially be operated with fi in the range of 1 MHz to 5 MHz.
* Character frame during answer to reset
""""""""""""""""""""""""""""""""""""""

www.cardwerk.com/.../smartcard_standard_ISO7816-3.aspx

We understand initial fi should be 3571200 .
Because initial etu is 1/9600 s
This understand is not corect ?

Best Regards
Hiroyasu

Hello Hiroyasu

I believe so you are right on the calculations.

Regards
Amit

Hi,Amit

If My caluculations are right, Tiva should be get difference TX/RX clock.
Tiva's data sheet says ISO7816 on UART module.

We wanna know how to setup difference clock

Best Regards
Hiroyasu

Hello Hiroyasu

No. If you check the document. The bit rate is the same as clock and suggested rate is between 7-50KHz.

b - Answer to Reset in synchronous transmission
-------------------------------------------
* Clock frequency and bit rate
""""""""""""""""""""""""""""
There is a linear relationship between the bit rate on the I/O line and the clock frequency provided by the clock interface device on CLK.

Any clock frequency between 7kHz and 50kHz may be chosen for the reset sequence. A clock frequency of 7kHz corresponds to 7kbit/s, and values of the clock frequency up to 50kHz cause corresponding bit rates to be transmitted.

Regards
Amit

Hi,Amit

I wanna make sure that.

Renesas SH7721 support ISO7816.

We wanna do same thing on TM4C129x.

SH7720 Group, SH7721 Group
User's Manual: Hardware
documentation.renesas.com/.../r01uh0083ej_sh7720_hm.pdf

30.5 Usage Notes


Can Tiva do same thing ?

Best Regards
Hiroyasu

Hello Hiroyasu,

I am not sure what is meant by the "Basic clock" in the timing diagram. I guess it refers to the internal clock and not the clock on the TXD pin?

Regards
Amit

Hi, Amit

I heard this clock should be send from TX pin if ISO7816 is supported
Can Tiva send from this Basic clock ?

Best Regards
Hiroyasu

Hello Hiroyasu,

Yes. The data sheet shows that in case of ISO7816 mode, the UTX pin shall have the clock and URX pin shall eb used for half duplex data exchange.

Regards
Amit

Hi, Amit

Thank you for your reply.
I understand Basic clock you told me is same clock of TX/RX.
Can Tiva's RX clock * 372 send from TX Pin like Renesas device?

I try to make initial code.
but We can not get RX clock * 372 clock from TX pin

=======================
-Initial code
// Set the clocking to run directly from the crystal at 120MHz.
//
g_ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
SYSCTL_OSC_MAIN |
SYSCTL_USE_PLL |
SYSCTL_CFG_VCO_480), 120000000);
//
// Enable the GPIO port that is used for the on-board LED.
//
ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPION);

//
// Enable the GPIO pins for the LED (PN0).
//
ROM_GPIOPinTypeGPIOOutput(GPIO_PORTN_BASE, GPIO_PIN_0);

//
// Enable the peripherals used by this example.
//
ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_UART4);
ROM_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOK);

//
// Enable processor interrupts.
//
ROM_IntMasterEnable();

//
// Set GPIO PK0 and PK1 as UART pins.
//
GPIOPinConfigure(GPIO_PK0_U4RX);
GPIOPinConfigure(GPIO_PK1_U4TX);
ROM_GPIOPinTypeUART(GPIO_PORTK_BASE, GPIO_PIN_0 | GPIO_PIN_1);

//Smart Card mode Enable
UARTSmartCardEnable(UART4_BASE);

//
// Configure the UART for 115,200, 8-N-1 operation.
//
ROM_UARTConfigSetExpClk(UART4_BASE, g_ui32SysClock, 9600,
(UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
UART_CONFIG_PAR_NONE));

//
// Enable the UART interrupt.
//
ROM_IntEnable(INT_UART4);
ROM_UARTIntEnable(UART4_BASE, UART_INT_RX | UART_INT_RT);
=======================

Best Regards
Hiroyasu

Hello Hiroyasu,

You need to program the clock by changing the parameter 9600 to the Clock value desired.

ROM_UARTConfigSetExpClk(UART4_BASE, g_ui32SysClock, 9600,
(UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
UART_CONFIG_PAR_NONE));

Regards
Amit

Hi, Amit

I have to say again.
We wanna know How to set these difference TX/RX clock configuration
on ISO7816 Smart Card mode like Renesas device.

RX ... 9600
TX ... 9600 * 372

Can Tiva set this Configration?
Don't you know that?

Best Regards
Hiroyasu

Hello Hiroyasu,

AFAIK, the ISO7816 interface does not require to change the clock rate for TX and RX as they are baud rate fixed.

Regards
Amit

Hi, Amit

I think you are wrong.
Because Renesas device support ISO7816 supports different clock.

I wanna just know how to set different clock on Tiva like Renesas device.
Can Tiva set different clock ?

Best Regards
Hiroyasu

Hi, Amit

Thank you for you reply.
I wanna make sure it means Tiva can not do reconfiguration ?

Best Regards
Hiroyasu

Hi, Amit

Thnak you!I got it.

Best Regards
Hiroyasu

Hello Hiroyasu

You are welcome. However considering the post details, I would like to have an application note on the same done, so that it can be used as a future reference. In case you are interested then please do send me a PM to discuss this offline.

Regards
Amit

Hi,　Amit

I sent you frendship message for sending PM.
Please check.

and I have more quetions.

1.I wanna make sure whether Tiva can send clock from TX "pin".
We was talking about only different clock of TX/RX.
If Tiva can send clock from TX "pin", Let me know.

2.What does TI think Hardware structure for Samrt Card mode of Tiva?

Best Regards
Hiroyasu

Hi, Amit

About 1.
I wanna make sure whether Tiva can send clock(RX*372) from TX "pin".

Best Regards
Hiroyasu

Hello Hiroyasu,

What is the RX clock frequency we are talking about. I have asked this question as it should not be that RX*372 exceeds the programming parameters of the UART Baud Rate.

Regards
Amit

Hi,Amit

I think RX is baud rate(ex. 9600bps).
We were talking about difference clock TX and RX.
I think this discuss is not from TX "pin".

In my next question, Can TX "pin" output RX (baud rate clock) *372  on Tiva?

Best Regards
Hiroyasu

Hello Hiroyasu

Yes, it can send 9600bps*372 when the Baud Rate register is reconfigured.

Regards
Amit

Hi, Amit

I understand you told me Tiva can send 9600bps*372 from TX pin,
if Tiva can reconfigured.
and In this case, I guess RX baud rate become 9600bps*372.

I wanna make sure that Tiva can become

RX ... 9600bps
from TX pin ... 9600 * 372

Is this possible on Tiva ?

Best Regards
Hiroyasu

Hello Hiroyasu,

If you perform TX of 9600*372, then immediately after transmit operation you would need to configure the baud rate for 9600 so that RX may be done.

Regards
Amit

Hi,Amit

O.K. I understand Tiva can not send difference RX clock from TX pin.
and I have another question.

Can you show me Hardware structure TI think for Samrt Card mode of Tiva?

Best Regards
Hiroyasu

Hello Hiroyasu

What exactly do you mean by hardware structure. A reference design or the logic design of the ISO7816 in the device?

Regards
Amit

Hi, Amit

Yes,I want logic design and reference design.

Best Regards
Hiroyasu

Hello Hiroyasu,

We do not have a reference design for ISO7815 yet. Also the logic design is strictly a TI internal data that cannot be shared on a public forum. Also no vendor open sources or publishes the same.

Regards
Amit

Hi, Amit

Is it difficult to show easily Block Diagram
If you signed an NDA regulation with my customer, Can you share your logic design information ?

Best Regards
Hiroyasu

Hello Hiroyasu,

The Block diagram in the datasheet is the only customer facing diagram available. The internal logic design may not be shared with customers. You may want to check with the field teams as well.

Regards
Amit