NEC PD78058FY(A) Network Card User Manual


 
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CHAPTER 26
µ
PD78P058F, 78P058FY
The
µ
PD78P058F and 78P058FY are products which have one time PROM incorporated into them, which it is only
possible to write to once. The differences between PROM products (
µ
PD78P058F and 78P058FY) and ROM products
(
µ
PD78056F, 78056FY, 78058F and 78058FY) are shown in Table 26-1.
Table 26-1. Differences Between
µ
PD78P058F, 78P058FY and Mask ROM Versions
Item
µ
PD78P058F, 78P058FY Mask ROM version
Internal ROM structure One-time PROM Mask ROM
Internal ROM capacity 60 Kbytes
µ
PD78056F, 78056FY: 48 Kbytes
µ
PD78058F, 78058FY: 60 Kbytes
Internal expansion RAM capacity 1024 bytes
µ
PD78056F, 78056FY: None
µ
PD78058F, 78058FY: 1024 bytes
Changing internal ROM and internal high- Enable
Note 1
Disable
speed RAM capacities with memory size
switching register
Changing of internal expansion RAM Enable
Note 2
Disable
capacity by internal expansion RAM size
switching register
IC pin None Available
VPP pin Available None
Pins P60 to P63 pull resistance on-chip None Available
mask option
Electrical characteristics Refer to the separate Data Sheet.
Notes 1. Through the RESET input, the internal PROM capacity becomes 60 Kbytes and the internal high speed
RAM capacity becomes 1024 bytes.
2. Through the RESET input, the internal expansion RAM capacity becomes 1024 bytes.
Caution In PROM products and mask ROM products, the noise resistance and noise emissions differ. In
the process from prototype production to volume production, if the switchover from PROM
product to ROM product is studied, carry out a thorough evaluation of the CS products (not ES
products) among the mask ROM products.
Remark Only the
µ
PD78058F and 78058FY, 78P058F, 78P058FY are provided with an internal expansion RAM
size switching register.