MPC823 datasheet(43/74 Pages) MOTOROLA

43 / 74 page

Communication Processor Module

MOTOROLA

MPC823 REFERENCE MANUAL

16-421

10. Initialize the TX buffer descriptor and assume the TX data buffer is at 0x00002000 in

main memory and contains five 8-bit characters. Write 0xB000 to TX_BD_Status,

0x0005 to TX_BD_Length, and 0x00002000 to TX_BD_Pointer.

11. Write 0xFF to the SMCE–Transparent register to clear any previous events.

12. Write 0x13 to the SMCM–Transparent register to enable all possible serial

management controller interrupts.

13. Write 0x00000010 to the CIMR to allow SMC1 to generate a system interrupt. The

CICR must also be initialized.

14. Write 0x3830 to the SMCMR to configure 8-bit characters, unreversed data, and

normal operation (not loopback). Notice that the transmitter and receiver have not

been enabled yet.

15. Write 0x3833 to the SMCMR to enable the SMCx transmitter and receiver. This

additional write ensures that the TEN and REN bits are enabled last.

16.11.7.15 SMC1 TRANSPARENT TSA PROGRAMMING EXAMPLE. The following is

an example initialization sequence for the SMC1 transparent channel over the time-slot

assigner. It is assumed that the time-slot assigner and TDM pins have already been set up

to route time-slot data to the SMC1 transmitter and receiver. Refer to Section 16.7 The

Serial Interface with Time-Slot Assigner for examples of how to configure the time-slot

assigner. The transmit and receive clocks and synchronization signals are provided

internally from the time-slot assigner.

1. Write RBASE and TBASE in the SMC1 parameter RAM to point to the RX buffer

descriptor and TX buffer descriptor in the dual-port RAM. Assuming one RX buffer

descriptor at the beginning of the dual-port RAM and one TX buffer descriptor following

that RX buffer descriptor, write RBASE with 0x2000 and TBASE with 0x2008.

2. Program the CPCR to execute the INIT TX AND RX PARAMS command. Write

0x0091 to the CPCR.

3. Write 0x0001 to the SDCR to initialize the SDMA configuration register.

4. Write 0x18 to RFCR and TFCR for normal operation.

5. Write MRBLR with the maximum number of bytes per receive buffer. Assume 16

bytes, so MRBLR = 0x0010.

6. Initialize the RX buffer descriptor and assume the RX data buffer is at 0x00001000 in

main memory. Write 0xB000 to RX_BD_Status, 0x0000 to RX_BD_Length (optional),

and 0x00001000 to RX_BD_Pointer.

Note: After 5 bytes are transmitted, the TX buffer descriptor is closed and after 16 bytes

are received the receive buffer is closed too. Any data received after 16 bytes

causes a busy (out-of-buffers) condition since only one RX buffer descriptor is

prepared.

MPC823 Datasheet(PDF) 43 Page - Motorola, Inc