Power and Clocking
Note: If Hardware Reset is entered during Sleep Mode, the proper
Figure 8-1. Power-On Reset Timing
| tR_VCCQ | |
VCCQ, PWR_EN | tR_VCCN | |
| tD_VCCN | |
VCCN | tR_VCC | |
| ||
VCC | tD_VCC | |
tD_NTRST | ||
nTRST | ||
| ||
JTAG PINS | tD_JTAG | |
| ||
nRESET | tD_NRESET | |
|
nRESET_OUT | tD_OUT |
|
Note: nBATT_FAULT and nVDD_FAULT must be high before nRESET_OUT is deasserted or PXA250 enters Sleep Mode
Table 8-7. Power-On Timing Specifications
Symbol | Description | Min | Typical | Max |
|
|
|
|
|
tR_VCCQ | VCCQ Rise / Stabilization time | 0.01 ms | — | 100 ms |
tR_VCCN | VCCN Rise / Stabilization time | 0.01 ms | — | 100 ms |
tR_VCC | VCC, PLL_VCC Rise / Stabilization time | 0.01 ms | — | 10 ms |
tD_VCCN | Delay between VCCQ stable and VCCN applied | 0 ms | — | — |
tD_VCC | Delay from VCCN stable and VCC, PLL_VCC applied | 0 ms | — | — |
tD_NTRST | Delay between VCC, PLL_VCC stable and nTRST deasserted | 50 ms | — | — |
tD_JTAG | Delay between nTRST deasserted and JTAG pins active, with | 0.03 ms | — | — |
nRESET asserted | ||||
tD_NRESET | Delay between VCC, PLL_VCC stable and nRESET | 50 ms | — | — |
deasserted | ||||
tD_OUT | Delay between nRESET deasserted and nRESET_OUT | 18.1 ms | — | 18.2 ms |
deasserted |
8.5.3Hardware Reset Timing
The timing sequences shown in Figure
PXA250 and PXA210 Applications Processors Design Guide |