HD6413008VF25 Datasheet, PDF (450/688 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

13. Smart Card Interface
Interrupt Operations: The smart card interface has three interrupt sources: transmit-data-empty
(TXI), transmit/receive-error (ERI), and receive-data-full (RXI). The transmit-end interrupt
request (TEI) is not available in smart card mode.
A TXI interrupt is requested when the TEND flag is set to 1 in SSR. An RXI interrupt is requested
when the RDRF flag is set to 1 in SSR. An ERI interrupt is requested when the ORER, PER, or
ERS flag is set to 1 in SSR. These relationships are shown in table 13.8.
Table 13.8 Smart Card Interface Mode Operating States and Interrupt Sources
Operating State
Transmit Mode
Receive Mode
Normal operation
Error
Normal operation
Error
Flag
TEND
ERS
RDRF
PER, ORER
Enable Bit
TIE
RIE
RIE
RIE
Interrupt Source
TXI
ERI
RXI
ERI
Examples of Operation in GSM Mode: When switching between smart card interface mode and
software standby mode, use the following procedures to maintain the clock duty cycle.
• Switching from smart card interface mode to software standby mode
1. Set the P9₄ data register (DR) and data direction register (DDR) to the values for the fixed
output state in software standby mode.
2. Write 0 in the TE and RE bits in the serial control register (SCR) to stop transmit/receive
operations. At the same time, set the CKE1 bit to the value for the fixed output state in
software standby mode.
3. Write 0 in the CKE0 bit in SCR to stop the clock.
4. Wait for one serial clock cycle. During this period, the duty cycle is preserved and clock output
is fixed at the specified level.
5. Write H'00 in the serial mode register (SMR) and smart card mode register (SCMR).
6. Make the transition to the software standby state.
• Returning from software standby mode to smart card interface mode
1'. Clear the software standby state.
2'. Set the CKE1 bit in SCR to the value for the fixed output state at the start of software standby
(the current P9₄ pin state).
3'. Set smart card interface mode and output the clock. Clock signal generation is started with the
normal duty cycle.
Rev.4.00 Aug. 20, 2007 Page 404 of 638
REJ09B0395-0400