HYE18P32161AC Datasheet, PDF (16/33 Pages) Infineon Technologies AG – 32M Asynchronous/Page CellularRAM

HYE18P32161AC(-/L)70/85
32M Asynch/Page CellularRAM
Functional Description
2.3
Refresh Control Register
The Refresh Control Register (RCR) allows to save stand-by power additionally by making use of the
Temperature-Compensated Self Refresh (TCSR), Partial-Array Self Refresh (PASR) and Deep Power Down
(DPD) features. The Refresh Control Register is programmed via the Control Register Set command and retains
the stored information until it is reprogrammed or the device loses power.
Please note that the RCR contents can only be set or changed when the CellularRAM is in idle state.
RCR
Refresh Control Register
(ZZ, A19 = 00_B)
A20 A19 A18 A17 A16 A15 A14 A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
0 RS
0
PM TCSR DPD 0
PASR
Field Bits
RS
19
PM
7
TCSR [6:5]
DPD 4
Type¹⁾ Description
w
Register Select
0 set to 0 to select this RCR.
w
Page Mode Enable/Disable
In asynchronous operation mode the user has the option to toggle A0 - A3 in a random
way at higher rate (20 ns vs. 70 ns) to lower access times of subsequent reads with
16-word boundary. In synchronous mode this option has no effect. The max. page
length is 16 words.
Please note that as soon as page mode is enabled the CS1 low time restriction
applies. This means that the CS1 signal must not be kept low longer than t_CSL = 10 µs.
Please refer to Figure 11.
0 page mode disabled (default)
1 page mode enabled
w
Temperature Compensated Self Refresh
The 2-bit wide TCSR field features four different temperature ranges to adjust the
refresh period to the actual case temperature. Since DRAM technology requires higher
refresh rates at higher temperature this is a second method to lower power
consumption in case of low or medium temperatures.
11 +85 °C (default)
00 +70 °C
01 +45 °C
10 +15 °C
w
Deep Power Down Enable/Disable
The DPD control bit puts the CellularRAM device in an extreme low power mode
cutting current consumption to less than 25 µA. Stored memory data is not retained in
this mode, while the settings of control register, RCR is stored during DPD.
0 DPD enabled
1 DPD disabled (default)
Data Sheet
16
V2.0, 2003-12-16