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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)

FUN CTIO N

N UM BE R

FUN CTIO N

N AME

FUN CTIO N

A D D RESS

TAB LE OFFSET

ME MO RY

ENTR Y POINT

SU M M A RY

0 — — — Reserved.

1 flashWrite 0 085C0h Wr ites a wor d to the flash memory.

2 flashErasePage 1 085C1h E rases 1 page (256 wor ds) in flash me mory.

3 flashEraseAl l 2 08563h Eras es 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 incre ments DP [0].

6 moveD P0dec 5 08578h Reads a byte/word at DP [0 ] in flash memory , then decre ments D P [0].

7 moveDP1 6 0857Bh Reads a byte/word at DP [1 ] in flash memo ry.

8 moveDP1 inc 7 0857Eh Reads a byte/word at DP [1 ] in flash memo ry, then incre ments DP [1].

9 moveD P1dec 8 08581h Reads a byte/word at DP [1 ] in flash memory , then decre ments D P [1].

10 moveFP 9 08584h Reads a byte/word at BP [O FFS] 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 memo ry, then decrements OFFS.

13 copyBuffer 12 0858Dh Cop ies LC [0] values fro m D P [0 ] to BP [O FFS].

14 UARTloader* 13 0859Eh This is the entry point to call the UART bootloader fro m an app lication.

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 UAR

T with LIN communication and

Section 13 for in-system pr

ogramming thr

ough UAR

T (and JT

AG).

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