diff --git a/cpu/i386/sc520/sc520.c b/cpu/i386/sc520/sc520.c
index 1d79210..4b566a7 100644
--- a/cpu/i386/sc520/sc520.c
+++ b/cpu/i386/sc520/sc520.c
@@ -33,75 +33,35 @@
 /*
  * utility functions for boards based on the AMD sc520
  *
- * void write_mmcr_byte(u16 mmcr, u8 data)
- * void write_mmcr_word(u16 mmcr, u16 data)
- * void write_mmcr_long(u16 mmcr, u32 data)
- *
- * u8   read_mmcr_byte(u16 mmcr)
- * u16  read_mmcr_word(u16 mmcr)
- * u32  read_mmcr_long(u16 mmcr)
- *
  * void init_sc520(void)
  * unsigned long init_sc520_dram(void)
  */
 
-static u32 mmcr_base= 0xfffef000;
-
-void write_mmcr_byte(u16 mmcr, u8 data)
-{
-	writeb(data, mmcr+mmcr_base);
-}
-
-void write_mmcr_word(u16 mmcr, u16 data)
-{
-	writew(data, mmcr+mmcr_base);
-}
-
-void write_mmcr_long(u16 mmcr, u32 data)
-{
-	writel(data, mmcr+mmcr_base);
-}
-
-u8 read_mmcr_byte(u16 mmcr)
-{
-	return readb(mmcr+mmcr_base);
-}
-
-u16 read_mmcr_word(u16 mmcr)
-{
-	return readw(mmcr+mmcr_base);
-}
-
-u32 read_mmcr_long(u16 mmcr)
-{
-	return readl(mmcr+mmcr_base);
-}
-
+volatile sc520_mmcr_t *sc520_mmcr = (sc520_mmcr_t *)0xfffef000;
 
 void init_sc520(void)
 {
 	/* Set the UARTxCTL register at it's slower,
 	 * baud clock giving us a 1.8432 MHz reference
 	 */
-	write_mmcr_byte(SC520_UART1CTL, 7);
-	write_mmcr_byte(SC520_UART2CTL, 7);
+	sc520_mmcr->uart1ctl = 0x07;
+	sc520_mmcr->uart2ctl = 0x07;
 
 	/* first set the timer pin mapping */
-	write_mmcr_byte(SC520_CLKSEL, 0x72);	/* no clock frequency selected, use 1.1892MHz */
+	sc520_mmcr->clksel = 0x72;	/* no clock frequency selected, use 1.1892MHz */
 
 	/* enable PCI bus arbitrer */
-	write_mmcr_byte(SC520_SYSARBCTL,0x02);  /* enable concurrent mode */
+	sc520_mmcr->sysarbctl = 0x02;	/* enable concurrent mode */
 
-	write_mmcr_word(SC520_SYSARBMENB,0x1f); /* enable external grants */
-	write_mmcr_word(SC520_HBCTL,0x04);      /* enable posted-writes */
-
+	sc520_mmcr->sysarbmenb = 0x1f;	/* enable external grants */
+	sc520_mmcr->hbctl = 0x04;	/* enable posted-writes */
 
 	if (CONFIG_SYS_SC520_HIGH_SPEED) {
-		write_mmcr_byte(SC520_CPUCTL, 0x2);	/* set it to 133 MHz and write back */
+		sc520_mmcr->cpuctl = 0x02;	/* set it to 133 MHz and write back */
 		gd->cpu_clk = 133000000;
 		printf("## CPU Speed set to 133MHz\n");
 	} else {
-		write_mmcr_byte(SC520_CPUCTL, 1);	/* set CPU to 100 MHz and write back cache */
+		sc520_mmcr->cpuctl = 0x01;	/* set it to 100 MHz and write back */
 		printf("## CPU Speed set to 100MHz\n");
 		gd->cpu_clk = 100000000;
 	}
@@ -114,7 +74,7 @@
 	    "loop 0b\n": : : "ecx");
 
 	/* turn on the SDRAM write buffer */
-	write_mmcr_byte(SC520_DBCTL, 0x11);
+	sc520_mmcr->dbctl = 0x11;
 
 	/* turn on the cache and disable write through */
 	asm("movl	%%cr0, %%eax\n"
@@ -156,10 +116,9 @@
 		val = 3;  /* 62.4us */
 	}
 
-	write_mmcr_byte(SC520_DRCCTL, (read_mmcr_byte(SC520_DRCCTL) & 0xcf) | (val<<4));
+	sc520_mmcr->drcctl = (sc520_mmcr->drcctl & 0xcf) | (val<<4);
 
-	val = read_mmcr_byte(SC520_DRCTMCTL);
-	val &= 0xf0;
+	val = sc520_mmcr->drctmctl & 0xf0;
 
 	if (cas_precharge_delay==3) {
 		val |= 0x04;   /* 3T */
@@ -174,12 +133,12 @@
 	} else {
 		val |= 1;
 	}
-	write_mmcr_byte(SC520_DRCTMCTL, val);
+	sc520_mmcr->drctmctl = val;
 #endif
 
 	/* We read-back the configuration of the dram
 	 * controller that the assembly code wrote */
-	dram_ctrl = read_mmcr_long(SC520_DRCBENDADR);
+	dram_ctrl = sc520_mmcr->drcbendadr;
 
 	bd->bi_dram[0].start = 0;
 	if (dram_ctrl & 0x80) {
@@ -232,7 +191,7 @@
 {
 	printf("Resetting using SC520 MMCR\n");
 	/* Write a '1' to the SYS_RST of the RESCFG MMCR */
-	write_mmcr_word(SC520_RESCFG, 0x0001);
+	sc520_mmcr->rescfg = 0x01;
 
 	/* NOTREACHED */
 }
diff --git a/cpu/i386/sc520/sc520_pci.c b/cpu/i386/sc520/sc520_pci.c
index 871ad0a..f446c6d 100644
--- a/cpu/i386/sc520/sc520_pci.c
+++ b/cpu/i386/sc520/sc520_pci.c
@@ -33,23 +33,23 @@
 	u16 level_reg;
 	u8 level_bit;
 } sc520_irq[] = {
-	{ SC520_IRQ0,  SC520_MPICMODE,  0x01 },
-	{ SC520_IRQ1,  SC520_MPICMODE,  0x02 },
-	{ SC520_IRQ2,  SC520_SL1PICMODE, 0x02 },
-	{ SC520_IRQ3,  SC520_MPICMODE,  0x08 },
-	{ SC520_IRQ4,  SC520_MPICMODE,  0x10 },
-	{ SC520_IRQ5,  SC520_MPICMODE,  0x20 },
-	{ SC520_IRQ6,  SC520_MPICMODE,  0x40 },
-	{ SC520_IRQ7,  SC520_MPICMODE,  0x80 },
+	{ SC520_IRQ0,  0, 0x01 },
+	{ SC520_IRQ1,  0, 0x02 },
+	{ SC520_IRQ2,  1, 0x02 },
+	{ SC520_IRQ3,  0, 0x08 },
+	{ SC520_IRQ4,  0, 0x10 },
+	{ SC520_IRQ5,  0, 0x20 },
+	{ SC520_IRQ6,  0, 0x40 },
+	{ SC520_IRQ7,  0, 0x80 },
 
-	{ SC520_IRQ8,  SC520_SL1PICMODE, 0x01 },
-	{ SC520_IRQ9,  SC520_SL1PICMODE, 0x02 },
-	{ SC520_IRQ10, SC520_SL1PICMODE, 0x04 },
-	{ SC520_IRQ11, SC520_SL1PICMODE, 0x08 },
-	{ SC520_IRQ12, SC520_SL1PICMODE, 0x10 },
-	{ SC520_IRQ13, SC520_SL1PICMODE, 0x20 },
-	{ SC520_IRQ14, SC520_SL1PICMODE, 0x40 },
-	{ SC520_IRQ15, SC520_SL1PICMODE, 0x80 }
+	{ SC520_IRQ8,  1, 0x01 },
+	{ SC520_IRQ9,  1, 0x02 },
+	{ SC520_IRQ10, 1, 0x04 },
+	{ SC520_IRQ11, 1, 0x08 },
+	{ SC520_IRQ12, 1, 0x10 },
+	{ SC520_IRQ13, 1, 0x20 },
+	{ SC520_IRQ14, 1, 0x40 },
+	{ SC520_IRQ15, 1, 0x80 }
 };
 
 
@@ -77,34 +77,34 @@
 
 	/* first disable any non-pci interrupt source that use
 	 * this level */
-	for (i=SC520_GPTMR0MAP;i<=SC520_GP10IMAP;i++) {
-		if (i>=SC520_PCIINTAMAP&&i<=SC520_PCIINTDMAP) {
-			continue;
-		}
-		if (read_mmcr_byte(i) == sc520_irq[irq].priority) {
-			write_mmcr_byte(i, SC520_IRQ_DISABLED);
-		}
+
+	/* PCI interrupt mapping (A through D)*/
+	for (i=0; i<=3 ;i++) {
+		if (sc520_mmcr->pci_int_map[i] == sc520_irq[irq].priority)
+			sc520_mmcr->pci_int_map[i] = SC520_IRQ_DISABLED;
+	}
+
+	/* GP IRQ interrupt mapping */
+	for (i=0; i<=10 ;i++) {
+		if (sc520_mmcr->gp_int_map[i] == sc520_irq[irq].priority)
+			sc520_mmcr->gp_int_map[i] = SC520_IRQ_DISABLED;
 	}
 
 	/* Set the trigger to level */
-	write_mmcr_byte(sc520_irq[irq].level_reg,
-			read_mmcr_byte(sc520_irq[irq].level_reg) | sc520_irq[irq].level_bit);
+	sc520_mmcr->pic_mode[sc520_irq[irq].level_reg] =
+		sc520_mmcr->pic_mode[sc520_irq[irq].level_reg] | sc520_irq[irq].level_bit;
 
 
 	if (pci_pin < 4) {
 		/* PCI INTA-INTD */
 		/* route the interrupt */
-		write_mmcr_byte(SC520_PCIINTAMAP + pci_pin, sc520_irq[irq].priority);
-
-
+		sc520_mmcr->pci_int_map[pci_pin] = sc520_irq[irq].priority;
 	} else {
 		/* GPIRQ0-GPIRQ10 used for additional PCI INTS */
-		write_mmcr_byte(SC520_GP0IMAP + pci_pin - 4, sc520_irq[irq].priority);
+		sc520_mmcr->gp_int_map[pci_pin - 4] = sc520_irq[irq].priority;
 
 		/* also set the polarity in this case */
-		write_mmcr_word(SC520_INTPINPOL,
-				read_mmcr_word(SC520_INTPINPOL) | (1 << (pci_pin-4)));
-
+		sc520_mmcr->intpinpol = sc520_mmcr->intpinpol | (1 << (pci_pin-4));
 	}
 
 	/* register the pin */
diff --git a/cpu/i386/sc520/sc520_ssi.c b/cpu/i386/sc520/sc520_ssi.c
index dd667ca..8dbe17a 100644
--- a/cpu/i386/sc520/sc520_ssi.c
+++ b/cpu/i386/sc520/sc520_ssi.c
@@ -61,32 +61,34 @@
 		temp |= PHS_INV_ENB;
 	}
 
-	write_mmcr_byte(SC520_SSICTL, temp);
+	sc520_mmcr->ssictl = temp;
 
 	return 0;
 }
 
 u8 ssi_txrx_byte(u8 data)
 {
-	write_mmcr_byte(SC520_SSIXMIT, data);
-	while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
-	write_mmcr_byte(SC520_SSICMD, SSICMD_CMD_SEL_XMITRCV);
-	while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
-	return read_mmcr_byte(SC520_SSIRCV);
+	sc520_mmcr->ssixmit = data;
+	while (sc520_mmcr->ssista & SSISTA_BSY);
+	sc520_mmcr->ssicmd = SSICMD_CMD_SEL_XMITRCV;
+	while (sc520_mmcr->ssista & SSISTA_BSY);
+
+	return sc520_mmcr->ssircv;
 }
 
 
 void ssi_tx_byte(u8 data)
 {
-	write_mmcr_byte(SC520_SSIXMIT, data);
-	while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
-	write_mmcr_byte(SC520_SSICMD, SSICMD_CMD_SEL_XMIT);
+	sc520_mmcr->ssixmit = data;
+	while (sc520_mmcr->ssista & SSISTA_BSY);
+	sc520_mmcr->ssicmd = SSICMD_CMD_SEL_XMIT;
 }
 
 u8 ssi_rx_byte(void)
 {
-	while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
-	write_mmcr_byte(SC520_SSICMD, SSICMD_CMD_SEL_RCV);
-	while ((read_mmcr_byte(SC520_SSISTA)) & SSISTA_BSY);
-	return read_mmcr_byte(SC520_SSIRCV);
+	while (sc520_mmcr->ssista & SSISTA_BSY);
+	sc520_mmcr->ssicmd = SSICMD_CMD_SEL_RCV;
+	while (sc520_mmcr->ssista & SSISTA_BSY);
+
+	return sc520_mmcr->ssircv;
 }
diff --git a/cpu/i386/sc520/sc520_timer.c b/cpu/i386/sc520/sc520_timer.c
index 2a3425b..23de14b 100644
--- a/cpu/i386/sc520/sc520_timer.c
+++ b/cpu/i386/sc520/sc520_timer.c
@@ -30,29 +30,29 @@
 void sc520_timer_isr(void)
 {
 	/* Ack the GP Timer Interrupt */
-	write_mmcr_byte (SC520_GPTMRSTA, 0x02);
+	sc520_mmcr->gptmrsta = 0x02;
 }
 
 int timer_init(void)
 {
 	/* Map GP Timer 1 to Master PIC IR0  */
-	write_mmcr_byte (SC520_GPTMR1MAP, 0x01);
+	sc520_mmcr->gp_tmr_int_map[1] = 0x01;
 
 	/* Disable GP Timers 1 & 2 - Allow configuration writes */
-	write_mmcr_word (SC520_GPTMR1CTL, 0x4000);
-	write_mmcr_word (SC520_GPTMR2CTL, 0x4000);
+	sc520_mmcr->gptmr1ctl = 0x4000;
+	sc520_mmcr->gptmr2ctl = 0x4000;
 
 	/* Reset GP Timers 1 & 2 */
-	write_mmcr_word (SC520_GPTMR1CNT, 0x0000);
-	write_mmcr_word (SC520_GPTMR2CNT, 0x0000);
+	sc520_mmcr->gptmr1cnt = 0x0000;
+	sc520_mmcr->gptmr2cnt = 0x0000;
 
 	/* Setup GP Timer 2 as a 100kHz (10us) prescaler */
-	write_mmcr_word (SC520_GPTMR2MAXCMPA, 83);
-	write_mmcr_word (SC520_GPTMR2CTL, 0xc001);
+	sc520_mmcr->gptmr2maxcmpa = 83;
+	sc520_mmcr->gptmr2ctl = 0xc001;
 
 	/* Setup GP Timer 1 as a 1000 Hz (1ms) interrupt generator */
-	write_mmcr_word (SC520_GPTMR1MAXCMPA, 100);
-	write_mmcr_word (SC520_GPTMR1CTL, 0xe009);
+	sc520_mmcr->gptmr1maxcmpa = 100;
+	sc520_mmcr->gptmr1ctl = 0xe009;
 
 	/* Register the SC520 specific timer interrupt handler */
 	register_timer_isr (sc520_timer_isr);
@@ -62,7 +62,7 @@
 	unmask_irq (0);
 
 	/* Clear the GP Timer 1 status register to get the show rolling*/
-	write_mmcr_byte (SC520_GPTMRSTA, 0x02);
+	sc520_mmcr->gptmrsta = 0x02;
 
 	return 0;
 }
@@ -71,12 +71,13 @@
 {
 	int m = 0;
 	long u;
+	long temp;
 
-	read_mmcr_word (SC520_SWTMRMILLI);
-	read_mmcr_word (SC520_SWTMRMICRO);
+	temp = sc520_mmcr->swtmrmilli;
+	temp = sc520_mmcr->swtmrmicro;
 
 	do {
-		m += read_mmcr_word (SC520_SWTMRMILLI);
-		u = read_mmcr_word (SC520_SWTMRMICRO) + (m * 1000);
+		m += sc520_mmcr->swtmrmilli;
+		u = sc520_mmcr->swtmrmicro + (m * 1000);
 	} while (u < usec);
 }