Datasheet

685
32133D–11/2011
UC3D
14. 0xXX (CRC MSB)
15. 0xXX (CRC LSB)
The length field is set to 0x0009 because there are 9 bytes of additional data: 5 address and size
bytes and 4 bytes of data. The address and size field indicates that words should be written to
address 0x500000004. The data written to 0x500000004 is 0xCAFEBABE.
31.4.7.10 MEMORY_READ
This command enables reading of memory/registers on the Service Access Bus (SAB). The
MEMORY_READ command allows words, halfwords, and bytes to be read from a continuous
sequence of addresses in one operation. The user must supply:
1. The size of the data field: 7 (size and starting address + read length indicator) in the
length field.
2. The size of the transfer: Words, halfwords, or bytes.
3. The starting address of the transfer.
4. The number of
bytes to read (max 65532).
The 4 MSB of the 36 bit SAB address are submitted together with the size field (2 bits). The 4
remaining address bytes are submitted before the number of bytes to read. The size of the
transfer is specified using the values from the following table:
Below is an example read command:
1. 0x55 (sync)
2. 0x81 (command)
3. 0x00 (length MSB)
4. 0x07 (length LSB)
5. 0x25 (size and address MSB, the two MSB of this byte are unused and set to zero)
6. 0x00
7. 0x00
8. 0x00
9. 0x04 (address LSB)
10. 0x00
Table 31-19. MEMORY_WRITE Details
Command Details
Command value 0x80
Additional data Size, Address and Data
Possible responses
0xC2: MEMORY_READWRITE_STATUS (Section 31.4.8.5)
0x41: NACK (Section 31.4.8.2)
Table 31-20. Size Field Decoding
Size field Description
00 Byte transfer
01 Halfword transfer
10 Word transfer
11 Reserved