diff --git a/flash.h b/flash.h
index bfb0a49..59f7cd4 100644
--- a/flash.h
+++ b/flash.h
@@ -208,6 +208,7 @@
 #define TEST_BAD_READ	(1 << 5)
 #define TEST_BAD_ERASE	(1 << 6)
 #define TEST_BAD_WRITE	(1 << 7)
+#define TEST_BAD_EW	(TEST_BAD_ERASE | TEST_BAD_WRITE)
 #define TEST_BAD_REW	(TEST_BAD_READ | TEST_BAD_ERASE | TEST_BAD_WRITE)
 #define TEST_BAD_PREW	(TEST_BAD_PROBE | TEST_BAD_READ | TEST_BAD_ERASE | TEST_BAD_WRITE)
 #define TEST_BAD_MASK	0xf0
diff --git a/flashchips.c b/flashchips.c
index 8289788..683af3c 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -5909,6 +5909,22 @@
 
 	{
 		.vendor		= "Macronix",
+		.name		= "MX23L3254",
+		.bustype	= BUS_SPI,
+		.manufacture_id	= MACRONIX_ID,
+		.model_id	= MACRONIX_MX23L3254,
+		.total_size	= 4096,
+		.page_size	= 256,
+		.tested		= TEST_OK_PR | TEST_BAD_EW,
+		.probe		= probe_spi_rdid,
+		.probe_timing	= TIMING_ZERO,
+		.write		= NULL, /* MX23L3254 is a mask ROM, so it is read-only */
+		.read		= spi_chip_read, /* Fast read (0x0B) supported */
+		.voltage	= {3000, 3600},
+	},
+
+	{
+		.vendor		= "Macronix",
 		.name		= "MX25L512(E)/MX25V512(C)",
 		.bustype	= BUS_SPI,
 		.manufacture_id	= MACRONIX_ID,
diff --git a/flashchips.h b/flashchips.h
index 8cbf299..6db6b74 100644
--- a/flashchips.h
+++ b/flashchips.h
@@ -423,13 +423,13 @@
 
 #define ISSI_ID			0xD5	/* ISSI Integrated Silicon Solutions */
 
-/*
- * MX25 chips are SPI, first byte of device ID is memory type,
+#define MACRONIX_ID		0xC2	/* Macronix (MX) */
+/* Mask ROMs */
+#define MACRONIX_MX23L3254	0x0516
+/* MX25 chips are SPI, first byte of device ID is memory type,
  * second byte of device ID is log(bitsize)-9.
  * Generalplus SPI chips seem to be compatible with Macronix
- * and use the same set of IDs.
- */
-#define MACRONIX_ID		0xC2	/* Macronix (MX) */
+ * and use the same set of IDs. */
 #define MACRONIX_MX25L512	0x2010	/* Same as MX25L512E, MX25V512, MX25V512C */
 #define MACRONIX_MX25L1005	0x2011	/* Same as MX25L1005C, MX25L1006E */
 #define MACRONIX_MX25L2005	0x2012	/* Same as MX25L2005C */
@@ -448,6 +448,7 @@
 #define MACRONIX_MX25U12835E	0x2538	/* Same as MX25U12835F */
 #define MACRONIX_MX25U25635F	0x2539
 #define MACRONIX_MX25L3235D	0x5E16	/* MX25L3225D/MX25L3235D/MX25L3237D */
+
 #define MACRONIX_MX29F001B	0x19
 #define MACRONIX_MX29F001T	0x18
 #define MACRONIX_MX29F002B	0x34	/* Same as MX29F002NB; N has reset pin n/c. */