ez80190 ZiLOG Semiconductor, ez80190 Datasheet - Page 72

• Manufacturer Part Number: ez80190
• Description: Ez80190 Microprocessor
• Manufacturer: ZiLOG Semiconductor

PS006613-0306
RAM Control Registers
Bit
Position
7
GPRAM_EN
6
MACRAM_EN
[5:0]
Bit
Reset
CPU Access
Note: R/W = Read/Write.
range that is covered by both the RAM address space and a particular Memory
Chip Select address space, the Memory Chip Select is not activated.
RAM Control Register
The internal RAM spaces, data RAM and Multiply-Accumulator RAM, can be
enabled by setting corresponding bits in this register.
RAM Address Upper Byte Register
The RAM_ADDR_U register defines the upper byte of the address for the two on-
chip RAM blocks—general-purpose RAM and MACC RAM. If either or both of
these on-chip RAM blocks are enabled, their addresses assume priority over any
Chip Selects. The external Chip Select signals are not asserted if the correspond-
ing RAM address is enabled.
Value
0
1
0
1
000000 Reserved
R/W
Description
On-chip general-purpose RAM is disabled.
On-chip general-purpose RAM is enabled.
On-chip multiply-accumulator RAM is disabled.
On-chip multiply-accumulator RAM is enabled.
7
0
Table 21. RAM Control Register
R/W
(RAM_CTL = B4h)
6
0
PRELIMINARY
R
5
0
R
4
0
R
3
0
eZ80190 Product Specification
R
2
0
Random Access Memory
R
1
0
R
0
0
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