Boot ROM
MCF5253 Reference Manual, Rev. 1
Freescale Semiconductor
19-3
;
/* Disable ACRs */
moveq.l
#0,d0
movec
d0,ACR0
movec
d0,ACR1
;
/* Initialize SRAMBAR */
move.l
#SR1,d0;
/* locate SRAM0, validate it! */
movec
d0,SRAMBAR
move.l
#SR1,d0;
/* locate SRAM1, validate it! */
movec
d0,SRAMBAR1
move.l
#1,d0;
/* locate MBAR and validate */
movec
d0,MBAR;
move.l
#_1,d0;
/* locate MBAR2 and validate*/
movec
d0,MBAR2;
;
/* Initialize CS0 */
move.l
#ROMbase,d0;
move.l
d0,CSAR0;
/* locate ROM */
move.l
#0xFFFF0001,d0;
/* block size 64 KB, validate */
move.l
d0,CSMR0;
move.l
#0x0580,d0;
/* port size 16 bit, AA, 1WS */
move.l
d0,CSCR0;
move.l
#___SP_INIT,sp
move.w
#0x2000,SR;
/* enable interrupts */
jsr
_main
bra
.;
/* loop in case main returns */
19.2.2
Boot Type Detection
Three GPIO lines define the boot mode and device type. After initialization of the on-chip resources, the
boot loader reads the status of the GPIO lines and selects the requested device to boot from. Boot type
encoding is described in
.
Table 19-1. Boot Detection GPIO
Boot Mode
GPIO50
GPIO49
GPIO48
I
2
C master
0
0
0
SPI (master)
0
0
1
IDE (master)
0
1
0
I
2
C slave
1
0
0
UART (5.6448/11.2896 MHz Xtal)
1
0
1
UART (8.4672/16.9344/33.8688 MHz Xtal)
1
1
0
UART (5/10/20 MHz Xtal)
1
1
1
Summary of Contents for MCF5253
Page 1: ...Document Number MCF5253RM Rev 1 08 2008 MCF5253 Reference Manual...
Page 26: ...MCF5253 Reference Manual Rev 1 xxvi Freescale Semiconductor...
Page 32: ...MCF5253 Reference Manual Rev 1 xxxii Freescale Semiconductor...
Page 46: ...MCF5253 Introduction MCF5253 Reference Manual Rev 1 1 14 Freescale Semiconductor...
Page 62: ...Signal Description MCF5253 Reference Manual Rev 1 2 16 Freescale Semiconductor...
Page 98: ...Instruction Cache MCF5253 Reference Manual Rev 1 5 10 Freescale Semiconductor...
Page 104: ...Static RAM SRAM MCF5253 Reference Manual Rev 1 6 6 Freescale Semiconductor...
Page 128: ...Synchronous DRAM Controller Module MCF5253 Reference Manual Rev 1 7 24 Freescale Semiconductor...
Page 144: ...Bus Operation MCF5253 Reference Manual Rev 1 8 16 Freescale Semiconductor...
Page 176: ...System Integration Module SIM MCF5253 Reference Manual Rev 1 9 32 Freescale Semiconductor...
Page 198: ...Analog to Digital Converter ADC MCF5253 Reference Manual Rev 1 12 6 Freescale Semiconductor...
Page 246: ...DMA Controller MCF5253 Reference Manual Rev 1 14 18 Freescale Semiconductor...
Page 282: ...UART Modules MCF5253 Reference Manual Rev 1 15 36 Freescale Semiconductor...
Page 344: ...Audio Interface Module AIM MCF5253 Reference Manual Rev 1 17 46 Freescale Semiconductor...
Page 362: ...I2 C Modules MCF5253 Reference Manual Rev 1 18 18 Freescale Semiconductor...
Page 370: ...Boot ROM MCF5253 Reference Manual Rev 1 19 8 Freescale Semiconductor...