
2000 Feb 21
19
Philips Semiconductors
Product specication
Multiprotocol IC Card coupler
TDA8006
handbook, full pagewidth
MGR232
I/O
SS
RIU
CMDVCC
P4
FF
R/W
EN
INT
FSD
RBF
release reset
set start session
set CMDVCC
first start
read status
int cleared
anything
buffer full
read status
read character
and int cleared
reset start session
10.5 ETU
Fig.8 First character reception.
TRANSMISSION
Transmission mode is selected when TRN is HIGH.
If enabled, an interrupt occurs on the rising edge of TRN,
indicating that the transmission buffer is empty and ready
to accept a character for transmission. The interrupt is
cleared during the read status operation. The character is
written to the UTR on the falling edge of EN during the
write operation, and starts to be transmitted on the rising
edge of EN.
The I/O line is read at 10.84 ETU to check if the card has
detected a parity error. At the same time, bit TBE is set in
the USR, and, if enabled, an interrupt occurs to indicate
that the transmission buffer is empty, and that a new
character may be written. If the parity is correct, the
transmission of the next character will start at
12 ETU + GT + 0.5 ETU after the start bit of the previous
character (see Section “Extra guard time”). If the parity is
not correct, then assuming that a character has been
written to the UTR, the transmission starts at 13 ETU (the
guard time GT must be programmed before transmitting).
Bit LCT can be used for cards that are required to change
from transmission to reception mode very fast. If LCT is set
HIGH, then the UART automatically resets
bits TRN and LCT at 10.85 ETU if no parity error has
occurred; the UART is ready to receive a character from
the card at 12 ETU (T = 0) or 11 ETU (T = 1) after the
previous start bit. If a parity error has occurred during
transmission of the last character, then the UART stays in
transmission mode with LCT set, waiting for the software
to rewrite the corrupted character.