SPE Series Differences

Signature block structure for 16 bit ('F149/'F169) versions

typedef struct {
    word    CodeCRC;
    word    CheckWord;
    struct {
        word    StartAddr;
        word    EndAddr;
        } BlkCRC[2];
    char    Signature[34];
    } SPESigBlk;

Signature block structure for 20 bit ('F2618) version

In this version the fields have been re-ordered to put the CRC last. This allows for a single address range to cover from the start of code to the byte before the CRC. The second address range would normally cover the extended memory and the third would be spare. Note that the addresses are now extended to dwords.

typedef struct {
    char    Signature[48];
    struct {
        dword   StartAddr;
        dword   EndAddr;
        } BlkCRC[3];
    dword   SpareDWord;
    word    CheckWord;
    word    CodeCRC;
    } SPEXSigBlk;