Section 18 ROM (Mask ROM Version/ZTAT Version)
18.1
Overview
The size of the on-chip ROM is 60 kbytes in the H8/3337Y and H8/3397, 48 kbytes in the
H8/3336Y and H8/3396, and 32 kbytes in the H8/3334Y and H8/3394. The on-chip ROM is
connected to the CPU via a 16-bit data bus. Both byte data and word data are accessed in two
states, enabling rapid data transfer.
The on-chip ROM is enabled or disabled depending on the inputs at the mode pins (MD1 and
MD0). See table 18.1.
Table 18.1 On-Chip ROM Usage in Each MCU Operating Mode
Mode Pins
Mode
MD1
0
MD0
1
On-Chip ROM
Disabled (external addresses)
Enabled
Mode 1 (expanded mode)
Mode 2 (expanded mode)
Mode 3 (single-chip mode)
1
0
1
1
Enabled
The PROM versions (H8/3337Y ZTAT and H8/3334Y ZTAT) can be set to writer mode and
programmed with a general-purpose PROM programmer. In the H8/3337Y and H8/3397, the
accessible ROM addresses are H'0000 to H'EF7F (61,312 bytes) in mode 2, and H'0000 to H'F77F
(63,360 bytes) in mode 3. For details, see section 3, MCU Operating Modes and Address Space.
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RENESAS [ RENESAS TECHNOLOGY CORP ]
