Maxim Integrated MAXQ7667 - Manual (Page 308)

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MAXQ7667 User’s Guide
SECTION 18: UTILITY ROM
The ROM in the MAXQ7667 provides routines for handling the bootloader and application code, the debug engine, and some utility
function for the user. The focus of this section is the utility function. The area of the UROM where the utility functions reside is known
as the utility ROM.
The MAXQ7667 utility ROM includes routines that provide the following functions to application software:
• In-application programming routines for flash memory (program, erase, mass erase)
• Single word/byte copy and buffer copy routines for use with lookup tables in flash memory
To provide backward compatibility among different versions of the utility ROM, a function address table is included that contains the
entry points for all user-callable functions. With this table, user code can determine the entry point for a given function as follows:
1) Read the location of the function address table from address 0800Dh in the utility ROM.
2) The entry points for each function listed in Table 18-1 are contained in the function address table, one word per function, in the
order given by their function numbers.
For example, the entry point for the flashEraseAll function can be accessed and called by the following procedure.
get_urom_table_entry:
move dpc, #1Ch //all data pointers in word mode
move dp[0], #0800Dh //initialize dp[0]
move bp, @dp[0] //load function address table location in bp
move offs, #2 //load function number in offs
call @bp[offs] //call flashEraseAll
It is also possible to call utility ROM functions directly, using the memory entry points of the function given in Table 18-1. Standard
include files are provided for this purpose with the MAXQ7667 development tool set. This method calls functions more quickly, but the
application may need to be recompiled in order to run properly with a different version of the utility ROM.
Table 18-1. Utility ROM User Functions (for Utility ROM Version 1.01)
FUNCTION
NUMBER
FUNCTION
NAME
FUNCTION
ADDRESS
TABLE OFFSET
MEMORY
ENTRY POINT
SUMMARY
0 — — — Reserved.
1 flashWrite 0 085C0h Writes a word to the flash memory.
2 flashErasePage 1 085C1h Erases 1 page (256 words) in flash memory.
3 flashEraseAll 2 08563h Erases all flash memory.
4 moveDP0 3 08572h Reads a byte/word at DP[0] in flash memory.
5 moveDP0inc 4 08575h Reads a byte/word at DP[0] in flash memory, then increments DP[0].
6 moveDP0dec 5 08578h Reads a byte/word at DP[0] in flash memory, then decrements DP[0].
7 moveDP1 6 0857Bh Reads a byte/word at DP[1] in flash memory.
8 moveDP1inc 7 0857Eh Reads a byte/word at DP[1] in flash memory, then increments DP[1].
9 moveDP1dec 8 08581h Reads a byte/word at DP[1] in flash memory, then decrements DP[1].
10 moveFP 9 08584h Reads a byte/word at BP[OFFS] in flash memory.
11 moveFPinc 10 08587h Reads a byte/word at BP[OFFS] in flash memory, then increments OFFS.
12 moveFPdec 11 0858Ah Reads a byte/word at BP[OFFS] in flash memory, then decrements OFFS.
13 copyBuffer 12 0858Dh Copies LC[0] values from DP[0] to BP[OFFS].
14 UARTloader* 13 0859Eh This is the entry point to call the UART bootloader from an application.
15 AutoBaud* 14 085CEh
Waits for a 0x0D and measures the bit time for it, so that a value for the
baud clock can be calculated.
*See Section 8 for UART with LIN communication and Section 13 for in-system programming through UART (and JTAG).