Datasheet

Section 19 ROM
Rev.6.00 Sep. 27, 2007 Page 736 of 1268
REJ09B0220-0600
19.1.2 Register Configuration
The operating mode of the chip is controlled by the mode pins and the BCRL register. The ROM-
related registers are shown in table 19.1.
Table 19.1 ROM Registers
Register Name Abbreviation R/W Initial Value Address
*
Mode control register MDCR R/W Undefined H'FF3B
Bus controller register BCRL R/W Undefined H'FED5
Note: * Lower 16 bits of the address.
19.2 Register Descriptions
19.2.1 Mode Control Register (MDCR)
Bit : 7 6 5 4 3 2 1 0
— — — — — MDS2 MDS1 MDS0
Initial value : 1 0 0 0 0 —
*
—
*
—
*
R/W : — — — — — R R R
Note: * Determined by pins MD2 to MD0.
MDCR is an 8-bit read-only register used to monitor the current operating mode of the chip.
Bit 7—Reserved: This bit cannot be modified and is always read as 1.
Bits 6 to 3—Reserved: These bits cannot be modified and are always read as 0.
Bits 2 to 0—Mode Select 2 to 0 (MDS2 to MDS0): These bits indicate the input levels at pins
MD2 to MD0 (the current operating mode). Bits MDS2 to MDS0 correspond to pins MD2 to
MD0. MDS2 to MDS0 are read-only bits, and cannot be modified. The mode pin (MD2 to MD0)
input levels are latched into these bits when MDCR is read. These latches are canceled by a reset.