TDA8029 Datasheet, PDF (32/58 Pages) NXP Semiconductors – Low power single card reader

Philips Semiconductors
Low power single card reader
Product specification
TDA8029
8.10.2.2 UART Receive Register (URR)
Table 46 UART receive register, address Dh, read
BIT
Symbol
Reset value
7
UR7
0
6
UR6
0
5
UR5
0
4
UR4
0
3
UR3
0
2
UR2
0
1
UR1
0
0
UR0
0
Table 47 Description of register bits
BIT
7 to 0
SYMBOL
UR[7:0]
DESCRIPTION
UART receive bits. When the microcontroller wants to read data from the card, it reads
it from this register in direct convention:
• With a synchronous card, only UR0 is relevant and is a copy of the state of the selected
card I/O
• When needed, this register may be tied to a FIFO whose length ‘n’ is programmable
between 1 and 8; if n > 1, then no interrupt is given until the FIFO is full and the
controller may empty the FIFO when required
• With a parity error:
– In protocol T = 0, the received byte is not stored in the FIFO and the error counter is
incremented. The error counter is programmable between 1 and 8. When the
programmed number is reached, then bit PE is set in the status register USR and
INT0_N falls LOW. The error counter must be reprogrammed to the desired value
after its count has been reached
– In protocol T = 1, the character is loaded in the FIFO and the bit PE is set to the
programmed value in the parity error counter.
• When the FIFO is full, then bit RBF in the status register USR is set. This bit is reset
when at least one character has been read from URR
• When the FIFO is empty, then bit FE is set in the status register USR as long as no
character has been received.
2003 Oct 30
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