Operation In Gsm Mode - Hitachi H8S/2646 Hardware Manual

flag is set but the RDRF flag is not. Consequently, the DTC is not activated, but instead, an ERI
interrupt request is sent to the CPU. Therefore, the error flag should be cleared.
Note: For block transfer mode, see section 13.4, SCI Interrupts.
14.3.7

Operation in GSM Mode

Switching the Mode: When switching between smart card interface mode and software standby
mode, the following switching procedure should be followed in order to maintain the clock duty.
• When changing from smart card interface mode to software standby mode
[1] Set the data register (DR) and data direction register (DDR) corresponding to the SCK pin to
the value for the fixed output state in software standby mode.
[2] Write 0 to the TE bit and RE bit in the serial control register (SCR) to halt transmit/receive
operation. At the same time, set the CKE1 bit to the value for the fixed output state in software
standby mode.
[3] Write 0 to the CKE0 bit in SCR to halt the clock.
[4] Wait for one serial clock period.
During this interval, clock output is fixed at the specified level, with the duty preserved.
[5] Make the transition to the software standby state.
• When returning to smart card interface mode from software standby mode
[6] Exit the software standby state.
[7] Write 1 to the CKE0 bit in SCR and output the clock. Signal generation is started with the
normal duty.
[1] [2] [3]
Normal operation
[4] [5]
Figure 14-9 Clock Halt and Restart Procedure
Software
standby
Normal operation
[6] [7]
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