mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 857

• Manufacturer Part Number: mpc823rg
• Description: Mpc823 Powerquicc Integrated Communications Processor For Portable Systems
• Manufacturer: Freescale Semiconductor, Inc

16.11.6.16 HANDLING INTERRUPTS IN THE SMCx UART CONTROLLER. Follow
these steps to handle an interrupt in a serial management controller:
12. Initialize the RX buffer descriptor. Assume the RX data buffer is at 0x00001000 in main
13. Initialize the TX buffer descriptor. Assume the TX data buffer is at 0x00002000 in main
14. Write 0xFF to the SMCE–UART register to clear any previous events.
15. Write 0x17 to the SMCM–UART register to enable all possible serial management
16. Write 0x00000010 to the CIMR so SMC1 can generate a system interrupt. The CICR
17. Write 0x4820 to SMCMR to configure normal operation (not loopback), 8-bit
18. Write 0x4823 to SMCMR to enable the SMC1 transmitter and receiver. This additional
1. Once an interrupt occurs, read the SMCE–UART register to discover the cause of the
2. Process the TX buffer descriptor to reuse it if the TX bit is set in the SMCE–UART
3. Clear the SMCx bit in the CISR.
4. Execute the rfi instruction.
memory. Write 0xB000 to RX_BD_Status, 0x0000 to RX_BD_Length (not required),
and 0x00001000 to RX_BD_Pointer.
memory and contains five 8-bit characters. Then write 0xB000 to TX_BD_Status,
0x0005 to TX_BD_Length, and 0x00002000 to TX_BD_Pointer.
controller interrupts.
must also be initialized.
characters, no parity, 1 stop bit. Notice that the transmitter and receiver are not
enabled yet.
write ensures that the TEN and REN bits are enabled last.
interrupt. To clear the SMCE bits, write ones to them.
register. Extract data from the RX buffer descriptor if the RX bit is set in the
SMCE–UART. To transmit another buffer, set the R bit in the TX buffer descriptor.
Note: After 5 bytes are transmitted, the TX buffer descriptor is closed. The receive
buffer is closed after 16 bytes are received. Any data received after 16 bytes
causes a busy (out-of-buffers) condition since only one RX buffer descriptor is
prepared.
Freescale Semiconductor, Inc.
For More Information On This Product,
MPC823 REFERENCE MANUAL
Go to: www.freescale.com
Communication Processor Module
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