Maxim Integrated MAXQ Family Users Guide: MAXQ2000 Supplement - Manual (Page 58)

MAXQ Family User’s Guide:
MAXQ2000 Supplement
Bit 1: (ICDF.1) System Program Enable (SPE). This bit controls the behavior of the MAXQ2000 following reset.
0 = The MAXQ2000 jumps to application code (in flash/ROM) at 0000h following a reset.
1 = The MAXQ2000 executes the in-system programming bootloader following a reset.
Bits 2 and 3: (ICDF.2 and ICDF.3) Programming Source Select (PSS0 and PSS1). When SPE = 1, these bits determine which inter-
face is used for in-system programming operations.
Programming Source Select Values
Bits 4 to 7: (ICDF.4 to ICDF.7) Reserved
Bootloader Protocol
Regardless of which interface is being used (JTAG or Serial Port 0), the protocol for communicating with the bootloader follows the
same binary format. The following notes apply for each interface.
• When using the JTAG interface, the clock rate (TCK) must be kept below 1/8 the system clock rate.
• When using the Serial Port 0 interface, the bootloader autobauds to the serial baud rate being used by the host.
All bootloader commands begin with a single command byte. The high four bits of this command byte define the command family (from 0
to 15), while the low four bits define the specific command within that family. All commands (except for those in Family 0) follow this format:
After each command has completed, the loader outputs a “prompt” byte to indicate that it has fin-
ished the operation. The prompt byte is the single chararacter “>”.
Bootloader commands that fail for any reason set the bootloader status byte to an error code value describing the reason for the fail-
ure. See Table 26. This status byte can be read by means of the Get Status command (04h).
PSS1 PSS0 PROGRAMMING SOURCE
0 0 JTAG Interface
0 1 Serial Port 0 (UART)
1 0 reserved
1 1 reserved
STATUS VALUE FUNCTION
00 No Error. The last command completed successfully.
01 Family Not Supported. An attempt was made to use a command from a family the bootloader does not support.
02 Invalid Command. An attempt was made to use a nonexistent command within a supported command family.
03
No Password Match. An attempt was made to use a password-protected command without first matching a valid password.
Or, the Match Password command was called with an incorrect password value.
04 Bad Parameter. The parameter (address or otherwise) passed to the command was out of range or otherwise invalid.
05 Verify Failed. The verification step failed on a Load/Verify or Verify command.
06 Unknown Register. An attempt was made to read from or write to a nonexistent register.
07
Word Mode Not Supported. An attempt was made to set word mode access, but the bootloader supports byte mode access
only.
08 Master Erase Failed. The bootloader was unable to perform master erase.
BYTE 1 BYTE 2 BYTE 3 BYTE 4 (LENGTH) BYTES/WORDS
Command Length Param 1 Param 2 Data
Table 26. Bootloader Status Codes
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