diff --git a/src/soc/intel/baytrail/baytrail/iosf.h b/src/soc/intel/baytrail/baytrail/iosf.h
index 6ff087bdb6..444dc38fb1 100644
--- a/src/soc/intel/baytrail/baytrail/iosf.h
+++ b/src/soc/intel/baytrail/baytrail/iosf.h
@@ -51,6 +51,8 @@
 
 uint32_t iosf_bunit_read(int reg);
 void iosf_bunit_write(int reg, uint32_t val);
+uint32_t iosf_dunit_read(int reg);
+void iosf_dunit_write(int reg, uint32_t val);
 
 /* IOSF ports. */
 #define IOSF_PORT_AUNIT		0x00 /* IO Arbiter unit */
@@ -106,6 +108,20 @@ void iosf_bunit_write(int reg, uint32_t val);
 #define BUNIT_SMRRH		0x2f
 # define BUNIT_SMRR_ENABLE	(1 << 31)
 
+/*
+ * DUNIT Registers.
+ */
 
+#define DRP			0x00
+# define DRP_CH0_RANK0_EN	(0x01 << 0)
+# define DRP_CH0_RANK1_EN	(0x01 << 1)
+# define DRP_CH1_RANK0_EN	(0x01 << 2)
+# define DRP_CH1_RANK1_EN	(0x01 << 3)
+#define DTR0			0x01
+# define DTR0_SPEED_MASK	0x03
+# define DTR0_SPEED_800		0x00
+# define DTR0_SPEED_1066	0x01
+# define DTR0_SPEED_1333	0x02
+# define DTR0_SPEED_1600	0x03
 
 #endif /* _BAYTRAIL_IOSF_H_ */
diff --git a/src/soc/intel/baytrail/iosf.c b/src/soc/intel/baytrail/iosf.c
index 6d4cba9bb6..2373d81598 100644
--- a/src/soc/intel/baytrail/iosf.c
+++ b/src/soc/intel/baytrail/iosf.c
@@ -59,3 +59,24 @@ void iosf_bunit_write(int reg, uint32_t val)
 	write_iosf_reg(MCR_REG, cr);
 	write_iosf_reg(MDR_REG, val);
 }
+
+uint32_t iosf_dunit_read(int reg)
+{
+	uint32_t cr = IOSF_OPCODE(IOSF_OP_READ_SYSMEMC) |
+	              IOSF_PORT(IOSF_PORT_SYSMEMC) | IOSF_REG(reg) |
+	              IOSF_BYTE_EN;
+
+	write_iosf_reg(MCR_REG, cr);
+	return read_iosf_reg(MDR_REG);
+}
+
+void iosf_dunit_write(int reg, uint32_t val)
+{
+	uint32_t cr = IOSF_OPCODE(IOSF_OP_WRITE_SYSMEMC) |
+	              IOSF_PORT(IOSF_PORT_SYSMEMC) | IOSF_REG(reg) |
+	              IOSF_BYTE_EN;
+
+
+	write_iosf_reg(MCR_REG, cr);
+	write_iosf_reg(MDR_REG, val);
+}