TDA8031 Datasheet, PDF (23/57 Pages) NXP Semiconductors – USB smart card reader (OTP or ROM)

Philips Semiconductors
USB smart card reader (OTP or ROM)
Product specification
TDA8030; TDA8031
Table 19 Description of the UCR2 bits
BIT
SYMBOL
DESCRIPTION
27
ENINT1 Enable Interrupt 1: If bit ENINT1 = 1, then a HIGH-to-LOW transition on INT1 will
wake-up the microcontroller from power-down mode. When not in power-down mode,
bit ENINT1 has no effect.
26
DISTBE/ Disable TBE/RBF interrupts: If bit DISTBE/RBF = 1, then reception or transmission of a
RBF
character will not generate an interrupt. This feature is useful for increasing
communication speed with the card; in this case, the copy of TBE/RBF bit within the
MSR must be polled and not the original, in order not to loose priority interrupts which
can occur in the USR.
25
−
not used
24
−
not used
23
SAN
Synchronous/Asynchronous: Bit SAN is set by software if a synchronous card is
expected. Then, the UART is bypassed and only bit 0 in the URR and UTR is connected
to the I/O. In this case, the clock is controlled by bit SC in the CCR.
22
AUTOCONV Auto convention: If bit AUTOCONV = 1, then the convention is set by software with bit
CONV in the UART Configuration Register. If it is reset, then the configuration is
automatically detected on the first received character while the bit SS (Start Session) is
set.
21
CKU
Clock UART: Bit CKU is used to clock the UART at twice the clock frequency of the
card. An ETU will last 31 × PDR clock pulses if CKU = 0 and half if CKU = 1. It should
be noted that when CKU = 1 it has no effect if f_CLK = f_XTAL1. This means, for example,
that a baud rate of 76800 is not possible when the card is clocked with the frequency on
XTAL1.
20
PSC
Prescaler: If bit PSC = 1, then the prescaler value is 32. If PSC = 0, then the prescaler
value is 31. One ETU will last a number of cards clock cycles equal to PSC × PDR. All
baud rates specified in “ISO7816” norm are achievable with this configuration.
handbook, full pagewidth
CLK
2 × CLK
CKU
MUX
÷ 31 or 32
PSC
÷ PDR
MGU886
ETU
2003 Jul 04
Fig.6 ETU generation.
23